ORCID Profile
0000-0002-4568-8422
Current Organisation
University of Adelaide
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Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1CC16341H
Abstract: Highly ordered mesoporous Cr(2)O(3) materials with high specific surface area and narrow pore size distribution were successfully prepared by a vacuum assisted impregnation method. Both 2-dimensional hexagonal and 3-dimensional cubic Cr(2)O(3) mesoporous replicas from SBA-15 and KIT-6 templates exhibit enhanced performance for gas sensors and lithium ion batteries, compared to the bulk Cr(2)O(3) counterpart.
Publisher: Wiley
Date: 18-08-2023
Abstract: As a burgeoning electrolyte system, eutectic electrolytes based on ZnCl 2 /Zn(CF 3 SO 3 ) 2 /Zn(TFSI) 2 have been widely proposed in advanced Zn‐I 2 batteries however, safety and cost concerns significantly limit their applications. Here, we report new‐type ZnSO 4 ‐based eutectic electrolytes that are both safe and cost‐effective. Their universality is evident in various solvents of polyhydric alcohols, in which multiple −OH groups not only involve in Zn 2+ solvation but also interact with water, resulting in the high stability of electrolytes. Taking propylene glycol‐based hydrated eutectic electrolyte as an ex le, it features significant advantages in non‐flammability and low price that is /200 cost of Zn(CF 3 SO 3 ) 2 /Zn(TFSI) 2 ‐based eutectic electrolytes. Moreover, its effectiveness in confining the shuttle effects of I 2 cathode and side reactions of Zn anodes is evidenced, resulting in Zn‐I 2 cells with high reversibility at 1 C and 91.4 % capacity remaining under 20 C. After scaling up to the pouch cell with a record mass loading of 33.3 mg cm −2 , super‐high‐capacity retention of 96.7 % is achieved after 500 cycles, which exceeds other aqueous counterparts. This work significantly broadens the eutectic electrolyte family for advanced Zn battery design.
Publisher: Elsevier BV
Date: 12-2011
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM32173D
Publisher: Elsevier BV
Date: 11-2005
Publisher: Wiley
Date: 07-11-2018
Publisher: American Chemical Society (ACS)
Date: 12-2017
DOI: 10.1021/JACS.7B10817
Abstract: A major impediment to the electrocatalytic CO
Publisher: Wiley
Date: 25-11-2011
Publisher: Wiley
Date: 25-05-2020
Abstract: Electrochemical conversion of CO 2 into ethane is seldom observed because of the generally higher selectivity towards methane, ethylene, and ethanol. Consequently, little experimental evidence for its reaction mechanism exists and thus remains largely unknown. Now, by combining electrochemistry with in situ X‐ray absorption fine‐structure and in situ Raman techniques, iodide‐derived copper (ID‐Cu) and oxide‐derived copper (OD‐Cu) systems were studied to obtain a deeper understanding of the CO 2 to ethane mechanism. With trace iodine species on the surface and positively charged Cu species, production of ethane is significantly more favored on ID‐Cu compared to OD‐Cu, with higher selectivity and faster kinetics. For the first time, it is experimentally found that the formation of ethane follows the same pathway to ethylene and ethanol, and better stabilization of the late stage ethoxy intermediate can steer the reaction to ethane over ethanol.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM30501A
Publisher: Wiley
Date: 06-02-2022
Abstract: Dual‐atom catalysts (DACs) have become an emerging platform to provide more flexible active sites for electrocatalytic reactions with multi‐electron roton transfer, such as the CO 2 reduction reaction (CRR). However, the introduction of asymmetric dual‐atom sites causes complexity in structure, leaving an incomprehensive understanding of the inter‐metal interaction and catalytic mechanism. Taking NiCu DACs as an ex le, herein, a more rational structural model is proposed, and the distance‐dependent inter‐metal interaction is investigated by combining theoretical simulations and experiments, including density functional theory computation, aberration‐corrected transmission electron microscopy, synchrotron‐based X‐ray absorption fine structure, and Monte Carlo experiments. A distance threshold around 5.3 Å between adjacent NiN 4 and CuN 4 moieties is revealed to trigger effective electronic regulation and boost CRR performance on both selectivity and activity. A universal macro‐descriptor rigorously correlating the inter‐metal distance and intrinsic material features (e.g., metal loading and thickness) is established to guide the rational design and synthesis of advanced DACs. This study highlights the significance of identifying the inter‐metal interaction in DACs, and helps bridge the gap between theoretical study and experimental synthesis of atomically dispersed catalysts with highly correlated active sites.
Publisher: IOP Publishing
Date: 22-09-2008
DOI: 10.1088/0957-4484/19/43/435608
Abstract: We report a one-step synthesis of magnetic helical mesostructured silica (MHMS) by self-assembly of an achiral surfactant, magnetic nanocrystals with stearic acid ligands and silicate. This core-shell structured material consists of an Fe(3)O(4) superparamagnetic nanocrystal core and a highly ordered periodic helical mesoporous silica shell. We propose that the formation of the helical structure is induced by the interaction between the surfactant and dissociated stearic acid ligands. The MHMS obtained possesses superparamagnetism, uniform mesostructure, narrow pore size distribution, high surface area, and large pore volume. Furthermore, the drug release process is demonstrated using aspirin as a drug model and MHMS as a drug carrier in a sodium phosphate buffer solution.
Publisher: No publisher found
Date: 2022
Publisher: American Chemical Society (ACS)
Date: 23-04-2021
DOI: 10.1021/JACS.1C02379
Publisher: Wiley
Date: 20-04-2023
Abstract: Improving kinetics of solid‐state sulfide conversion in sulfur cathodes can enhance sulfur utilization of metal‐sulfur batteries. However, fundamental understanding of the solid‐state conversion remains to be achieved. Here, taking potassium‐sulfur batteries as a model system, we for the first time report the reducing overpotential of solid‐state sulfide conversion via the meta‐stable S 3 2− intermediates on transition metal single‐atom sulfur hosts. The catalytic sulfur host containing Cu single atoms demonstrates high capacities of 1595 and 1226 mAh g −1 at current densities of 335 and 1675 mA g −1 , respectively, with stable Coulombic efficiency of ≈100 %. Combined spectroscopic characterizations and theoretical computations reveal that the relatively weak Cu‐S bonding results in low overpotential of solid‐state sulfide conversion and high sulfur utilization. The elucidation of solid‐state sulfide conversion mechanism can direct the exploration of highly efficient metal‐sulfur batteries.
Publisher: Wiley
Date: 20-01-2022
Abstract: Magnesium batteries present high volumetric energy density and dendrite‐free deposition of Mg, drawing wide attention in energy‐storage devices. However, their further development remains stagnated due to relevant interfacial issues between the Mg anode and the electrolyte and sluggish solid‐state diffusion kinetics of Mg 2+ ions. Herein, an in situ conversion chemistry to construct a nanostructured Bi anode from bismuth selenide driven by Li + is proposed. Through the combination of operando synchrotron X‐ray diffraction, ex situ synchrotron X‐ray absorption spectroscopy, and comprehensive electrochemical tests, it is demonstrated that the nanosize of the in‐situ‐formed Bi crystals contributes to the fast Mg 2+ diffusion kinetics and highly efficient Mg–Bi alloingy/de‐alloying. The resultant Bi anodes exhibit superior long‐term cycling stability with over 600 cycles under a high current density of 1.0 A g ‐1 . This work provides a new approach to construct alloy anode and paves the way for exploring novel electrode materials for magnesium batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CC04231H
Abstract: Simultaneous oxidation state engineering of Co, N and S for cobalt nitride and sulfide electrocatalysts is demonstrated to facilitate intermediate desorption for OER and HER, leading to efficient overall water electrolysis in a neutral buffer electrolyte.
Publisher: Elsevier BV
Date: 08-2008
Publisher: Wiley
Date: 02-06-2014
Abstract: A new class of highly efficient oxygen evolution catalysts has been synthesized through the self-assembly of graphitic carbon nitride nanosheets and carbon nanotubes, driven by π-π stacking and electrostatic interactions. Remarkably, the catalysts exhibit higher catalytic oxygen evolution activity and stronger durability than Ir-based noble-metal catalysts and display the best performance among the reported nonmetal catalysts. This good result is attributed to the high nitrogen content and the efficient mass and charge transfer in the porous three-dimensional nanostructure.
Publisher: Elsevier BV
Date: 06-2009
Publisher: Wiley
Date: 14-11-2018
Publisher: Wiley
Date: 18-02-2008
Publisher: MDPI AG
Date: 18-12-2019
DOI: 10.3390/RS12010008
Abstract: Coastal erosion endangers millions living near-shore and puts coastal infrastructure at risk, particularly in low-lying deltaic coasts of developing nations. This study focuses on morphological changes along the ~320-km-long Sindh coastline of Pakistan over past three decades. In this study, the Landsat images from 1989 to 2018 at an interval of 10 years are used to analyze the state of coastline erosion. For this purpose, well-known statistical approaches such as end point rate (EPR), least median of squares (LMS), and linear regression rate (LRR) are used to calculate the rates of coastline change. We analyze the erosion trend along with the underlying controlling variables of coastal change. Results show that most areas along the coastline have experienced noteworthy erosion during the study period. It is found that Karachi coastline experienced 2.43 ± 0.45 m/yr of erosion and 8.34 ± 0.45 m/yr of accretion, while erosion on the western and eastern sides of Indus River reached 12.5 ± 0.55 and 19.96 ± 0.65 m/yr on average, respectively. Coastal erosion is widespread along the entire coastline. However, the rate of erosion varies across the study area with a general trend of erosion increasing from west to east in the Indus Delta region (IDR), and the highest average erosion rate is 27.46 m/yr. The interdecadal change during 1989–1999, 1999–2009 and 2009–2018 periods depicted an increasing linear trend (R2 = 0.78) from Karachi to Indus River (IR) East zone. The spatial trend from west to east is positively correlated with mean sea level rise, which has increased from 1.1 to 1.9 mm/year, and negatively correlated with topographic slope, which is found to be decreasing eastward along the coastline. The findings necessitate appropriate actions and have important implications to better manage coastal areas in Pakistan in the wake of global climate change.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8CS00848E
Abstract: A summary and analysis of approaches for measuring the surface areas of metal oxide electrocatalysts for evaluating their intrinsic electrocatalytic activity.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA02801C
Abstract: A new general strategy for breaking the limits imposed by volcano plots is proposed for the HER under alkaline conditions.
Publisher: Wiley
Date: 21-10-2008
Publisher: Wiley
Date: 05-08-2010
Publisher: Wiley
Date: 11-05-2021
Abstract: Present one‐step N 2 fixation is impeded by tough activation of the N≡N bond and low selectivity to NH 3 . Here we report fixation of N 2 ‐to‐NH 3 can be decoupled to a two‐step process with one problem effectively solved in each step, including: 1) facile activation of N 2 to NO x − by a non‐thermal plasma technique, and 2) highly selective conversion of NO x − to NH 3 by electrocatalytic reduction. Importantly, this process uses air and water as low‐cost raw materials for scalable ammonia production under ambient conditions. For NO x − reduction to NH 3 , we present a surface boron‐rich core–shell nickel boride electrocatalyst. The surface boron‐rich feature is the key to boosting activity, selectivity, and stability via enhanced NO x − adsorption, and suppression of hydrogen evolution and surface Ni oxidation. A significant ammonia production of 198.3 μmol cm −2 h −1 was achieved, together with nearly 100 % Faradaic efficiency.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6TA07547A
Abstract: Hybrid-structured solar cells with superior light absorption, charge separation and hole transportation exhibit enhanced photovoltaic performance.
Publisher: Wiley
Date: 11-10-2023
Publisher: Wiley
Date: 03-2022
DOI: 10.1002/SMM2.1109
Abstract: Converting CO 2 into high‐value fuels and chemicals by renewable‐electricity‐powered electrochemical CO 2 reduction reaction (CRR) is a viable approach toward carbon‐emissions‐neutral processes. Unlike the thermocatalytic hydrogenation of CO 2 at the solid‐gas interface, the CRR takes place at the three‐phase gas/solid/liquid interface near the electrode surface in aqueous solution, which leads to major challenges including the limited mass diffusion of CO 2 reactant, competitive hydrogen evolution reaction, and poor product selectivity. Here we critically examine the various methods of surface and interface engineering of the electrocatalysts to optimize the microenvironment for CRR, which can address the above issues. The effective modification strategies for the gas transport, electrolyte composition, controlling intermediate states, and catalyst engineering are discussed. The key emphasis is made on the erse atomic‐precision modifications to increase the local CO 2 concentration, lower the energy barriers for CO 2 activation, decrease the H 2 O coverage, and stabilize intermediates to effectively control the catalytic activity and selectivity. The perspectives on the challenges and outlook for the future applications of three‐phase interface engineering for CRR and other gas‐involving electrocatalytic reactions conclude the article.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CC05798C
Abstract: A new synthetic strategy was developed to prepare large-sized well-defined anatase TiO(2) nanosheets wholly dominated with thermodynamically unfavorable high-reactive {001} and {100} facets, which has a percentage of 98.7% and 1.3%, respectively. The as-prepared anatase TiO(2) nanosheets show a well-faceted morphology and have a large size in length (ca. 4.14 μm). The formation mechanism of the anatase TiO(2) nanosheets was also analyzed and investigated.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 06-2019
Publisher: Springer Science and Business Media LLC
Date: 20-09-2021
Publisher: Wiley
Date: 14-08-2014
Abstract: Composition-adjustable spinel-type metal oxides, Mnx Co3-x O4-δ (x=0.8-1.4), were synthesized in ethanol solutions by a rapid inorganic self-templating mechanism using KCl nanocrystals as the structure-directing agent. The Mnx Co3x O4δ materials showed ultrahigh oxygen evolution activity and strong durability in alkaline solutions, and are capable of delivering a current density of 10 mA cm(-2) at 1.58 V versus the reversible hydrogen electrode in 0.1 M KOH solution, which is superior in comparison to IrO2 catalysts under identical experimental conditions, and comparable to the most active noble-metal and transition-metal oxygen evolution electrocatalysts reported so far. The high performance for catalytic oxygen evolution originates from both compositional and structural features of the synthesized materials. The moderate content of Mn doping into the spinel framework led to their improved electronic conductivity and strong oxidizing ability, and the well-developed porosity, accompanied with the high affinity between OH(-) reactants and catalyst surface, contributed to the smooth mass transport, thus endowing them with superior oxygen evolution activity.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.BIORTECH.2010.08.110
Abstract: Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH. Electrochemical measurements show that the carbons made by impregnation-activation process have better capacitive behavior and higher capacitance retention ratio at high drain current than the carbons made by carbonization-activation process, which is due to that there are abundant macroscopic pores and less interior micropore surface in the texture of the former. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons and commercial wood-based active carbon, thus highlighting the success of preparing high performance electrode material for EDLC from SSS.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8TA11626A
Abstract: The dissociative chemisorption energy of water was proposed to address both thermodynamics and kinetics of alkaline hydrogen evolution.
Publisher: Wiley
Date: 04-10-2018
Abstract: Zinc-air batteries offer a possible solution for large-scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni-doped CoO nanosheets (NSs) for zinc-air batteries with superior high power density/energy density and durability is reported for the first time. In micro- and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR06111K
Abstract: By comparing hydrogen evolution reaction (HER) activities of Ru/MoS 2 /CP in alkaline and acidic solutions, a pH-dependent synergy has been identified on the Ru/MoS 2 interface for superior alkaline HER efficiency.
Publisher: American Chemical Society (ACS)
Date: 06-03-2009
DOI: 10.1021/LA900023P
Abstract: In this paper, we report the successful synthesis of amine-functionalized FDU-12-type mesoporous silica with a very large pore (30.2 nm) and a highly ordered mesostructure by using 3-aminopropyltriethoxysilane (APTES) as an organosilane source. Small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) measurements confirmed that the materials possessed a face-centered cubic (space group Fm3m) mesostructure. Different techniques were used to obtain a significant pore and entrance size enlargement: low synthesis temperature and high hydrothermal treatment temperature. The amount of amine organosilane influenced the mesostructure of the mesoporous silica. It was found that the addition of inorganic salt (KCl) could help to maintain an ordered structure of the large pore mesoporous material. X-ray photoelectron spectroscopy (XPS), solid-state magic-angle spinning (MAS) 13C nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA) verified the incorporation of amine functional groups on the surface of the materials. The addition of amine organosilane extended the synthesis temperature domain of ordered FDU-12 materials. The amine functional group significantly enhanced the adsorption capacity of the mesoporous materials, e.g., the amine functionalized mesoporous silica had 8-fold higher bovine serum albumin (BSA) adsorption capacity than that of the unfunctionalized one. It also had 2 times higher adsorption capacity for large cellulase enzymes. The amine functional group introduced positively charged groups on the surface of the mesoporous silica, which created strong electrostatic interactions between the protein and the silica.
Publisher: Wiley
Date: 28-12-2016
Publisher: Wiley
Date: 09-01-2023
Abstract: The design of heterogeneous catalysts is necessarily surface‐focused, generally achieved via optimization of adsorption energy and microkinetic modelling. A prerequisite is to ensure the adsorption energy is physically meaningful is the stable existence of the conceived active‐site structure on the surface. The development of improved understanding of the catalyst surface, however, is challenging practically because of the complex nature of dynamic surface formation and evolution under in‐situ reactions. We propose therefore data‐driven machine‐learning (ML) approaches as a solution. In this Minireview we summarize recent progress in using machine‐learning to search and predict (meta)stable structures, assist operando simulation under reaction conditions and micro‐environments, and critically analyze experimental characterization data. We conclude that ML will become the new norm to lower costs associated with discovery and design of optimal heterogeneous catalysts.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3TA02866F
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 08-2018
Publisher: Wiley
Date: 09-08-2023
Abstract: Rational design/fabrication of high‐activity photocatalysts is of central importance to realize solar‐to‐chemical conversion for tackling worldwide energy/environmental issues. Hence, it is desirable to disclose the element/space/time‐resolved charge kinetics and surface species evolution of photocatalysts under realistic conditions using various in situ characterizations. Furthermore, the correlation of the above‐disclosed mechanisms with atomic‐scale compositions/structures of photocatalysts can further direct the atomic‐level design/synthesis of high‐performance photocatalysts. Herein, Ru atoms incorporated CdS quantum dots (QDs) are synthesized using an in situ hot‐injection route. The optimized Ru incorporated CdS QDs (Ru0.1) exhibit excellent photocatalytic evolution rates of H 2 O 2 (8.78 mmol g −1 h −1 ) and benzaldehyde (11.70 mmol g −1 h −1 ), respectively. Four different in situ characterizations demonstrate that in realistic conditions, the incorporated Ru atoms with high oxidation state (+3) effectively attract photo‐generated electrons from bulk to the overall surface of Ru0.1 these directed electron flows also greatly facilitate the transfer of photo‐generated holes from bulk to surface of Ru0.1 via efficiently reducing electron‐hole recombination. in situ diffuse reflectance infrared Fourier transform spectroscopy, electron spin spectroscopy, and species‐trapping experiments further reveal three possible reaction pathways for H 2 O 2 evolution. This work underscores the use of in situ characterizations to reveal the element/space/time‐resolved electrons/holes kinetics and surface‐species generation for photocatalysts in realistic conditions.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4NR05451B
Abstract: Heterostructured BiOBr/Bi24O31Br10 nanocomposites with surface oxygen vacancies are constructed by a facile in situ route of one-step self-combustion of ionic liquids. The compositions can be easily controlled by simply adjusting the fuel ratio of urea and 2-bromoethylamine hydrobromide (BTH). BTH serves not only as a fuel, but also as a complexing agent for ionic liquids and a reactant to supply the Br element. The heterojunctions show remarkable adsorptive ability for both the cationic dye of rhodamine B (RhB) and the anionic dye of methylene orange (MO) at high concentrations, which is attributed to the abundant surface oxygen vacancies. The s le containing 75.2% BiOBr and 24.8% Bi24O31Br10 exhibits the highest photocatalytic activity. Its reaction rate constant is 4.0 and 9.0 times that of pure BiOBr in degrading 50 mg L(-1) of RhB and 30 mg L(-1) of MO under visible-light (λ > 400 nm) irradiation, respectively, which is attributed to the narrow band gap and highly efficient transfer efficiency of charge carriers. Different photocatalytic reaction processes and mechanisms over pure BiOBr and heterojunctions are proposed.
Publisher: Wiley
Date: 11-03-2020
Publisher: Wiley
Date: 12-2021
Abstract: Powered by inexhaustible solar energy, photoelectrochemical (PEC) hydrogen/ammonia production and reduction of carbon dioxide to high added‐value chemicals in eco‐friendly and mild conditions provide a highly attractive solution to carbon neutrality. Recently, substantial advances have been achieved in PEC systems by improving light absorption and charge separation/transfer in PEC devices. However, less attention is given to the atomic design of photoelectrocatalysts to facilitate the final catalytic reactions occurring at photoelectrode surface, which largely limits the overall photo‐to‐energy conversion of PEC system. Fundamental catalytic mechanisms and recent progress in atomic design of PEC materials are comprehensively reviewed by engineering of defect, dopant, facet, strain, and single atom to enhance the activity and selectivity. Finally, the emerging challenges and research directions in design of PEC systems for future photo‐to‐energy conversions are proposed.
Publisher: American Chemical Society (ACS)
Date: 27-04-2018
Publisher: American Chemical Society (ACS)
Date: 31-12-1999
DOI: 10.1021/IE990548I
Publisher: American Chemical Society (ACS)
Date: 27-02-2017
DOI: 10.1021/JACS.6B13100
Abstract: Organometallic complexes with metal-nitrogen/carbon (M-N/C) coordination are the most important alternatives to precious metal catalysts for oxygen reduction and evolution reactions (ORR and OER) in energy conversion devices. Here, we designed and developed a range of molecule-level graphitic carbon nitride (g-C
Publisher: IWA Publishing
Date: 2003
Abstract: A novel TiO2 coated haematite photocatalyst was prepared and used for removal of colored humic acids from wastewater in an UV bubble photocatalytic reactor. XRD analysis confirmed that nano-size anatase crystals of TiO2 were formed after calcination at 480°C. SEM results revealed that nano-size particles of TiO2 were uniformly coated on the surface of Fe2O3 to form a bulk of nano-structured photocatalyst Fe2O3/TiO2. The porous catalyst had a BET surface area of 168 m2/g. Both the color and total organic carbon (TOC) conversion versus the residence time were measured at various conditions. The effects of pH value, catalyst loaded, initial humic acid concentration and reaction temperature on conversion were monitored. The experimental results proved that the photocatalytic oxidation process was not temperature sensitive and the optimum catalyst loading was found to be 0.4 g/l. Degradation and decolorization of humic acids have higher efficiency in acidic medium and at low initial humic acid concentration. The new catalyst was effective in removing TOC at 61.58% and color400 at 93.25% at 180 minutes illumination time and for 20 mg/l neutral humic acid aqueous solution. The kinetic analysis showed that the rate of photocatalytic degradation of humic acids obeyed the first order reaction kinetics.
Publisher: Wiley
Date: 09-06-2017
Publisher: Springer Science and Business Media LLC
Date: 21-08-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA02486A
Abstract: A complex hydroxide/metal Ni(OH) 2 @Ni core–shell electrode was developed for a high-performance and flexible pseudocapacitor.
Publisher: Wiley
Date: 12-04-2017
Abstract: Nanostructured metal-contained catalysts are one of the most widely used types of catalysts applied to facilitate some of sluggish electrochemical reactions. However, the high activity of these catalysts cannot be sustained over a variety of pH ranges. In an effort to develop highly active and stable metal-contained catalysts, various approaches have been pursued with an emphasis on metal particle size reduction and doping on carbon-based supports. These techniques enhances the metal-support interactions, originating from the chemical bonding effect between the metal dopants and carbon support and the associated interface, as well as the charge transfer between the atomic metal species and carbon framework. This provides an opportunity to tune the well-defined metal active centers and optimize their activity, selectivity and stability of this type of (electro)catalyst. Herein, recent advances in synthesis strategies, characterization and catalytic performance of single atom metal dopants on carbon-based nanomaterials are highlighted with attempts to understand the electronic structure and spatial arrangement of in idual atoms as well as their interaction with the supports. Applications of these new materials in a wide range of potential electrocatalytic processes in renewable energy conversion systems are also discussed with emphasis on future directions in this active field of research.
Publisher: American Chemical Society (ACS)
Date: 15-04-2019
DOI: 10.1021/JACS.9B02124
Abstract: Electrochemical reduction of CO
Publisher: Wiley
Date: 18-07-2017
Publisher: Springer Science and Business Media LLC
Date: 17-09-2022
DOI: 10.1038/S41467-022-33258-0
Abstract: Electrosynthesis of urea from CO 2 and NO X provides an exceptional opportunity for human society, given the increasingly available renewable energy. Urea electrosynthesis is challenging. In order to raise the overall electrosynthesis efficiency, the most critical reaction step for such electrosynthesis, C-N coupling, needs to be significantly improved. The C-N coupling can only happen at a narrow potential window, generally in the low overpotential region, and a fundamental understanding of the C-N coupling is needed for further development of this strategy. In this regard, we perform ab initio Molecular Dynamics simulations to reveal the origin of C-N coupling under a small electrode potential window with both the dynamic nature of water as a solvent, and the electrode potentials considered. We explore the key reaction networks for urea formation on Cu(100) surface in neutral electrolytes. Our work shows excellent agreement with experimentally observed selectivity under different potentials on the Cu electrode. We discover that the * NH and * CO are the key precursors for C-N bonds formation at low overpotential, while at high overpotential the C-N coupling occurs between adsorbed * NH and solvated CO. These insights provide vital information for future spectroscopic measurements and enable us to design new electrochemical systems for more value-added chemicals.
Publisher: American Chemical Society (ACS)
Date: 05-2000
DOI: 10.1021/LA991613W
Publisher: Wiley
Date: 26-03-2010
Publisher: Elsevier BV
Date: 2009
Publisher: American Chemical Society (ACS)
Date: 07-02-2022
Publisher: Wiley
Date: 07-04-2020
Abstract: Single‐atom catalysts (SACs) have great potential in electrocatalysis. Their performance can be rationally optimized by tailoring the metal atoms, adjacent coordinative dopants, and metal loading. However, doing so is still a great challenge because of the limited synthesis approach and insufficient understanding of the structure–property relationships. Herein, we report a new kind of Mo SAC with a unique O,S coordination and a high metal loading over 10 wt %. The isolation and local environment was identified by high‐angle annular dark‐field scanning transmission electron microscopy and extended X‐ray absorption fine structure. The SACs catalyze the oxygen reduction reaction (ORR) via a 2 e − pathway with a high H 2 O 2 selectivity of over 95 % in 0.10 m KOH. The critical role of the Mo single atoms and the coordination structure was revealed by both electrochemical tests and theoretical calculations.
Publisher: American Chemical Society (ACS)
Date: 06-04-2022
Publisher: Wiley
Date: 09-2015
Abstract: The development of highly efficient and robust photocatalysts has attracted great attention for solving the global energy crisis and environmental problems. Herein, we describe the synthesis of a p–n heterostructured photocatalyst, consisting of ZnO nanorod arrays (NRAs) decorated with BiOI nanoplates (NPs), by a facile solvothermal method. The product thus obtained shows high photoelectrochemical water splitting performance and enhanced photoelectrocatalytic activity for pollutant degradation under visible light irradiation. The p‐type BiOI NPs, with a narrow band gap, not only act as a sensitizer to absorb visible light and promote electron transfer to the n‐type ZnO NRAs, but also increase the contact area with organic pollutants. Meanwhile, ZnO NRAs provide a fast electron‐transfer channel, thus resulting in efficient separation of photoinduced electron–hole pairs. Such a p–n heterojunction nanocomposite could serve as a novel and promising catalyst in energy and environmental applications.
Publisher: Wiley
Date: 10-06-2018
Abstract: Confined transformation of assembled two-dimensional MXene (titanium carbide) and reduced graphene oxide (rGO) nanosheets was employed to prepare the free-standing films of the integrated ultrathin sodium titanate (NTO) otassium titanate (KTO) nanosheets sandwiched between graphene layers. The ultrathin Ti-based nanosheets reduce the diffusion distance while rGO layers enhance conductivity. Incorporation of graphene into the titanate films produced efficient binder-free anodes for ion storage. The resulting flexible NTO/rGO and KTO/rGO electrodes exhibited excellent rate performances and long cycling stability characterized by reversible capacities of 72 mA h g
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 02-2006
Publisher: Elsevier BV
Date: 06-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2EE21653A
Publisher: Elsevier BV
Date: 06-2009
Publisher: Wiley
Date: 14-11-2018
Publisher: Wiley
Date: 18-04-2017
Abstract: Uniform Na
Publisher: Wiley
Date: 03-02-2020
Abstract: Cost-effective carbon-based catalysts are promising for catalyzing the electrochemical N
Publisher: Wiley
Date: 16-01-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 17-09-2014
DOI: 10.1039/C4TA04301D
Publisher: Hindawi Limited
Date: 28-09-2021
DOI: 10.1002/ER.7333
Publisher: American Chemical Society (ACS)
Date: 08-03-2012
DOI: 10.1021/IE300109U
Publisher: Wiley
Date: 21-07-2016
Publisher: Elsevier BV
Date: 2007
Publisher: Wiley
Date: 15-04-2013
Publisher: Wiley
Date: 10-2019
Abstract: Since first being reported as possible electrocatalysts to substitute platinum for the oxygen reduction reaction (ORR), carbon-based metal-free nanomaterials have been considered a class of promising low-cost materials for clean and sustainable energy-conversion reactions. However, beyond the ORR, the development of carbon-based catalysts for other electrocatalytic reactions is still limited. More importantly, the intrinsic activity of most carbon-based metal-free catalysts is inadequate compared to their metal-based counterparts. To address this challenge, more design strategies are needed in order to improve the overall performance of carbon-based materials. Herein, using water splitting as an ex le, some state-of-the-art strategies in promoting carbon-based nanomaterials are summarized, including graphene, carbon nanotubes, and graphitic-carbon nitride, as highly active electrocatalysts for hydrogen evolution and oxygen evolution reactions. It is shown that by rationally tuning the electronic and/or physical structure of the carbon nanomaterials, adsorption of reaction intermediates is optimized, consequently improving the apparent electrocatalytic performance. These strategies may facilitate the development in this area and lead to the discovery of advanced carbon-based nanomaterials for various applications in energy-conversion processes.
Publisher: American Chemical Society (ACS)
Date: 03-06-2009
DOI: 10.1021/IE900100G
Publisher: Springer Science and Business Media LLC
Date: 23-07-2015
DOI: 10.1038/NMAT4317
Abstract: Over the past decade, considerable progress has been made in the synthesis and applications of nanoporous carbon spheres ranging in size from nanometres to micrometres. This Review presents the primary techniques for preparing nanoporous carbon spheres and the seminal research that has inspired their development, presented potential applications and uncovered future challenges. First we provide an overview of the synthesis techniques, including the Stöber method and those based on templating, self-assembly, emulsion and hydrothermal carbonization, with special emphasis on the design and functionalization of nanoporous carbon spheres at the molecular level. Next, we cover the key applications of these spheres, including adsorption, catalysis, separation, energy storage and biomedicine — all of which might benefit from the regular geometry, good liquidity, tunable porosity and controllable particle-size distribution offered by nanoporous carbon spheres. Finally, we present the current challenges and opportunities in the development and commercial applications of nanoporous carbon spheres.
Publisher: Wiley
Date: 24-07-2019
Abstract: Common-metal-based single-atom catalysts (SACs) are quite difficult to design due to the complex synthesis processes required. Herein, we report a single-atom nickel iodide (SANi-I) electrocatalyst with atomically dispersed non-metal iodine atoms. The SANi-I is prepared via a simple calcination step in a vacuum-sealed oule and subsequent cyclic voltammetry activation. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and synchrotron-based X-ray absorption spectroscopy are applied to confirm the atomic-level dispersion of iodine atoms and detailed structure of SANi-I. Single iodine atoms are found to be isolated by oxygen atoms. The SANi-I is structural stable and shows exceptional electrocatalytic activity for the hydrogen evolution reaction (HER). In situ Raman spectroscopy reveals that the hydrogen adatom (H
Publisher: Wiley
Date: 16-04-2018
Publisher: Elsevier BV
Date: 2004
Publisher: Wiley
Date: 22-11-2022
Abstract: Efficient catalyst design is important for lean‐electrolyte sulfur reduction in Li−S batteries. However, most of the reported catalysts were focused on catalyst‐polysulfide interactions, and generally exhibit high activity only with a large excess of electrolyte. Herein, we proposed a general rule to boost lean‐electrolyte sulfur reduction by controlling the catalyst‐solvent interactions. As evidenced by synchrotron‐based analysis, in situ spectroscopy and theoretical computations, strong catalyst‐solvent interaction greatly enhances the lean‐electrolyte catalytic activity and battery stability. Benefitting from the strong interaction between solvent and cobalt catalyst, the Li−S battery achieves stable cycling with only 0.22 % capacity decay per cycle with a low electrolyte/sulfur mass ratio of 4.2. The lean‐electrolyte battery delivers 79 % capacity retention compared with the battery with flooded electrolyte, which is the highest among the reported lean‐electrolyte Li−S batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2CP44436D
Abstract: Microporous carbon materials with extremely small pore size are prepared by employing polyaniline as a carbon precursor and KOH as an activating agent. CO(2) sorption performance of the materials is systematically investigated at the temperatures of 0, 25 and 75 °C. The prepared carbons show very high CO(2) uptake of up to 1.86 and 1.39 mmol g(-1) under 1 bar, 75 °C and 0.15 bar, 25 °C, respectively. These values are amongst the highest CO(2) capture amounts of the known carbon materials. The relation between CO(2) uptake and pore size at different temperatures is studied. An interesting and innovative point that the micropores with pore size smaller than a critical value play a crucial role in CO(2) adsorption at different temperatures is demonstrated. It is found that the higher the sorption temperature is, the smaller this critical value of pore size is. Pores smaller than 0.54 nm are manifested to determine CO(2) capture capacity at high sorption temperature, e.g. 75 °C. This research proposes a basic principle for designing highly efficient CO(2) carbon adsorbents that is, the adsorbents should be primarily rich in extremely small micropores.
Publisher: Wiley
Date: 07-11-2013
Abstract: A highly hydrated structure was fabricated for catalyzing the oxygen evolution reaction (OER), which demonstrated significantly enhanced catalytic activity, favorable kinetics, and strong durability. The enhanced performance is correlated with the dual-active-site mechanism, and high hydrophilicity of the electrode can dramatically expedite the process of water oxidation into molecular oxygen.
Publisher: Wiley
Date: 14-02-2020
Publisher: Wiley
Date: 07-11-2018
Abstract: Lithium-sulfur batteries hold promise for next-generation batteries. A problem, however, is rapid capacity fading. Moreover, atomic-level understanding of the chemical interaction between sulfur host and polysulfides is poorly elucidated from a theoretical perspective. Here, a two-dimensional (2D) heterostructured MoN-VN is fabricated and investigated as a new model sulfur host. Theoretical calculations indicate that electronic structure of MoN can be tailored by incorporation of V. This leads to enhanced polysulfides adsorption. Additionally, in situ synchrotron X-ray diffraction and electrochemical measurements reveal effective regulation and utilization of the polysulfides in the MoN-VN. The MoN-VN-based lithium-sulfur batteries have a capacity of 708 mA h g
Publisher: Wiley
Date: 11-11-2014
Abstract: CdS nanoflake arrays (NFAs) exhibit unprecedented light absorption capability, and they can serve as a scaffold to load thin organic absorbers for extraordinarily high light absorption. As a result, the hybrid solar cell consisting of NFAs and organic absorber yields a ten-times high short-circuit photocurrent compared to the counterpart device with a common planar structure.
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 11-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TA00138A
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.JHAZMAT.2010.12.051
Abstract: Ordered mesoporous silicas with different pore structures, including SBA-15, MCM-41, MCM-48 and KIT-6, were functionalized with phenyltriethoxysilane by a post-synthesis grafting approach. It was found that phenyl groups were covalently anchored onto the surface of mesoporous silicas, and the long-range ordering of the mesoporous channels was well retained after the surface functionalization. The static adsorption of benzene and the dynamic adsorption of single component (benzene) and bicomponent (benzene and cyclohexane) on the original and functionalized materials were investigated. As indicated by the adsorption study, the functionalized silicas exhibit improvement in the surface hydrophobicity and affinity for aromatic compounds as compared with the original silicas. Furthermore, the pore structure and the surface chemistry of materials can significantly influence adsorption performance. A larger pore diameter and cubic pore structure are favorable to surface functionalization and adsorption performance. In particular, the best adsorption performance observed with phenyl-grafted KIT-6 is probably related to the highest degree of surface functionalization, arising from the relatively large mesopores and bi-continuous cubic pore structure which allow great accessibility for the functional groups. In contrast, functionalized MCM-41 exhibits the lowest adsorption efficiency, probably owing to the small size of mesopores and 1D mesoporous channels.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 12-2017
Publisher: Wiley
Date: 28-08-2018
Abstract: The realization of large-scale solar hydrogen (H
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4TB01601G
Abstract: Tunable stellate mesoporous silica nanoparticles are functionalized with low molecular poly(ethylene imine) for efficient label-free intracellular drug delivery.
Publisher: Wiley
Date: 10-11-2014
Abstract: The electrocatalytic hydrogen‐evolution reaction (HER), as the main step of water splitting and the cornerstone of exploring the mechanism of other multi‐electron transfer electrochemical processes, is the subject of extensive studies. A large number of high‐performance electrocatalysts have been developed for HER accompanied by recent significant advances in exploring its electrochemical nature. Herein we present a critical appraisal of both theoretical and experimental studies of HER electrocatalysts with special emphasis on the electronic structure, surface (electro)chemistry, and molecular design. It addresses the importance of correlating theoretical calculations and electrochemical measurements toward better understanding of HER electrocatalysis at the atomic level. Fundamental concepts in the computational quantum chemistry and its relation to experimental electrochemistry are also presented along with some featured ex les.
Publisher: Wiley
Date: 24-03-2023
Abstract: Solar hydrogen (H 2 ) generation via photocatalytic water splitting is practically promising, environmentally benign, and sustainably carbon neutral. It is important therefore to understand how to controllably engineer photocatalysts at the atomic level. In this work, atomic‐level engineering of defected ReSe 2 nanosheets (NSs) is reported to significantly boost photocatalytic H 2 evolution on various semiconductor photocatalysts including TiO 2 , CdS, ZnIn 2 S 4 , and C 3 N 4 . Advanced characterizations, such as atomic‐resolution aberration‐corrected scanning transmission electron microscopy (AC‐STEM), synchrotron‐based X‐ray absorption near edge structure (XANES), in situ X‐ray photoelectron spectroscopy (XPS), transient‐state surface photovoltage (SPV) spectroscopy, and transient‐state photoluminescence (PL) spectroscopy, together with theoretical computations confirm that the strongly coupled ReSe 2 /TiO 2 interface and substantial atomic‐level active sites of defected ReSe 2 NSs result in the significantly raised activity of ReSe 2 /TiO 2 . This work not only for the first time realizes the atomic‐level engineering of ReSe 2 NSs as a versatile platform to significantly raise the activities on different photocatalysts, but, more importantly, underscores the immense importance of atomic‐level synthesis and exploration on 2D materials for energy conversion and storage.
Publisher: Wiley
Date: 12-01-2015
Abstract: Poor cellular uptake of drug delivery carriers and uncontrolled drug release remain to be the major obstacles in cancer therapy due to their low delivery efficiency. In this study, a multifunctional intracellular GSH (glutathione)-responsive silica-based drug delivery system with enhanced cellular uptake capability is developed. Uniform 50 nm colloidal mesoporous silica nanoparticles (MSNs) with mercaptopropyl-functionalized core and silanol-contained silica surface (MSNs-SHin ) are designed and fabricated as a platform for drug covalent attachment and particle surface modification. Doxorubicin (DOX) with primary amine group as an anticancer model drug is covalently conjugated to the mesopores of MSNs-SHin via disulfide bonds in the presence of a heterobifunctional linker (N-Succinimidyl 3-(2-pyridyldithio) propionate). Poly(γ-glutamic acid) (γ-PGA) can be coated onto the particle surface by sequential electrostatic adsorption of polyethyleneimine (PEI) and γ-PGA. The constructed delivery system exhibits enhanced cellular uptake via a speculated γ-glutamyl transpeptidase (GGT)-mediated endocytosis pathway and controlled drug release capacity via intracellular GSH-responsive disulfide-bond cleavage, and thus significantly inhibits the growth of cancer cells. The multifunctional delivery system paves a new way for developing high-efficient particle-based nanotherapeutic approach for cancer treatment.
Publisher: Wiley
Date: 15-01-2021
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 05-2010
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2NR11691J
Abstract: In this proof-of-concept study, an agricultural biocide (imidacloprid) was effectively loaded into the mesoporous silica nanoparticles (MSNs) with different pore sizes, morphologies and mesoporous structures for termite control. This resulted in nanoparticles with a large surface area, tunable pore diameter and small particle size, which are ideal carriers for adsorption and controlled release of imidacloprid. The effect of pore size, surface area and mesoporous structure on uptake and release of imidacloprid was systematically studied. It was found that the adsorption amount and release profile of imidacloprid were dependent on the type of mesoporous structure and surface area of particles. Specifically, MCM-48 type mesoporous silica nanoparticles with a three dimensional (3D) open network structure and high surface area displayed the highest adsorption capacity compared to other types of silica nanoparticles. Release of imidacloprid from these nanoparticles was found to be controlled over 48 hours. Finally, in vivo laboratory testing on termite control proved the efficacy of these nanoparticles as delivery carriers for biopesticides. We believe that the present study will contribute to the design of more effective controlled and targeted delivery for other biomolecules.
Publisher: Elsevier BV
Date: 12-2007
DOI: 10.1016/J.JCIS.2007.08.047
Abstract: The phase transformation of mesostructured titanium phosphate (TiPO) from hexagonal to lamellar structure was observed in a simply hydrothermal treatment, accompanied by drastically morphological changes in the micrometer-sized particles. XRD pattern revealed that different mesostructures were obtained by simply varying hydrothermal temperature or treatment duration. SEM and TEM observations showed the morphological evolution from in idual particles to interconnected nanoplatelets. A significant blue shift in UV-vis spectra was observed for lamellar mesostructured material, which may be associated with the different coordinated Ti-sites in the hexagonal and lamellar mesostructures. FT-IR spectra and detailed (31)P MAS NMR studies indicated that additional POH groups were presented in the lamellar structure, which might play a key role in the structural and morphological transformations of mesostructures.
Publisher: American Chemical Society (ACS)
Date: 19-11-2005
DOI: 10.1021/IE050889Y
Publisher: Wiley
Date: 04-02-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CC09366F
Abstract: Hierarchical mesoporous yolk–shell structured carbon nanospheres show significantly enhanced electrochemical performance.
Publisher: Wiley
Date: 15-01-2013
Publisher: Wiley
Date: 04-07-2018
Abstract: Hollow structures exhibit fascinating and important properties for energy-related applications, such as lithium-ion batteries, supercapacitors, and electrocatalysts. Sodium-ion batteries, as analogs of lithium-ion batteries, are considered as promising devices for large-scale electrical energy storage. Inspired by applications of hollow structures as anodes for lithium-ion batteries, the application of these structures in sodium-ion batteries has attracted great attention in recent years. However, due to the difference in lithium and sodium-ion batteries, there are several issues that need to be addressed toward rational design of hollow structured sodium anodes. Herein, this research news article presents the recent developments in the synthesis of hollow structured anodes for sodium-ion batteries. The main strategies for rational design of materials for sodium-ion batteries are presented to provide an overview and perspectives for the future developments of this research area.
Publisher: American Chemical Society (ACS)
Date: 21-05-2009
DOI: 10.1021/JP810844P
Publisher: Elsevier BV
Date: 06-2015
Publisher: Springer Science and Business Media LLC
Date: 20-09-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TA00004A
Abstract: Two-dimensional (2D) MnO 2 ultrathin nanosheets have been assembled into three-dimensional (3D) aerogels, which can help prevent the restacking of 2D nanocrystals, and consequently lead to enhanced performances in Li–O 2 batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8MH00859K
Abstract: An alkaline-stable anionic Cd( ii ) boron imidazolate framework ( BIF-89 ) not only exhibits unique mechanochromic behavior, but also shows an enhanced oxygen evolution reaction (OER) catalytic activity due to the presence of uncoordinated −COO groups able to capture Fe at the atomic level.
Publisher: Wiley
Date: 27-01-2015
Publisher: Wiley
Date: 11-05-2021
Abstract: Present one‐step N 2 fixation is impeded by tough activation of the N≡N bond and low selectivity to NH 3 . Here we report fixation of N 2 ‐to‐NH 3 can be decoupled to a two‐step process with one problem effectively solved in each step, including: 1) facile activation of N 2 to NO x − by a non‐thermal plasma technique, and 2) highly selective conversion of NO x − to NH 3 by electrocatalytic reduction. Importantly, this process uses air and water as low‐cost raw materials for scalable ammonia production under ambient conditions. For NO x − reduction to NH 3 , we present a surface boron‐rich core–shell nickel boride electrocatalyst. The surface boron‐rich feature is the key to boosting activity, selectivity, and stability via enhanced NO x − adsorption, and suppression of hydrogen evolution and surface Ni oxidation. A significant ammonia production of 198.3 μmol cm −2 h −1 was achieved, together with nearly 100 % Faradaic efficiency.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TA09358J
Abstract: MoN nanosheets for the first time serve as a highly active co-catalyst to greatly enhance the photocatalytic H 2 production of TiO 2 .
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8TA01677A
Abstract: Cuprous ions incorporated into a ceria lattice for electrochemical reduction of CO 2 to ethylene with excellent selectivity and stability.
Publisher: Wiley
Date: 12-02-2018
Publisher: Wiley
Date: 06-10-2022
Abstract: The aggravating extreme climate changes and natural disasters stimulate the exploration of low‐carbon/zero‐carbon alternatives to traditional carbon‐based fossil fuels. Solar‐to‐hydrogen (STH) transformation is considered as appealing route to convert renewable solar energy into carbon‐free hydrogen. Restricted by the low efficiency and high cost of noble metal cocatalysts, high‐performance and cost‐effective photocatalysts are required to realize the realistic STH transformation. Herein, the 2D FePS 3 (FPS) nanosheets anchored with TiO 2 nanoparticles (TiO 2 /FePS 3 ) are synthesized and tested for the photocatalytic hydrogen evolution reaction. With the integration of FPS, the photocatalytic H 2 ‐evolution rate on TiO 2 /FePS 3 is radically increased by ≈1686%, much faster than that of TiO 2 alone. The origin of the greatly raised activity is revealed by theoretical calculations and various advanced characterizations, such as transient‐state photoluminescence spectroscopy/surface photovoltage spectroscopy, in situ atomic force microscopy combined with Kelvin probe force microscopy (AFM‐KPFM), in situ X‐ray photoelectron spectroscopy (XPS), and synchrotron‐based X‐ray absorption near edge structure. Especially, the in situ AFM‐KPFM and in situ XPS together confirm the electron transport pathway in TiO 2 /FePS 3 with light illumination, unveiling the efficient separation/transfer of charge carrier in TiO 2 /FePS 3 step‐scheme heterojunction. This work sheds light on designing and fabricating novel 2D material‐based S‐scheme heterojunctions in photocatalysis.
Publisher: Wiley
Date: 08-2019
Publisher: Wiley
Date: 05-11-2012
Abstract: I want to break free: Mesoporous silica nanoparticles are functionalized with sulfasalazine (SZ see scheme), a prodrug of 5-aminosalicylic acid (5-ASA) and sulfapyridine, to generate enzyme-responsive nanocarriers. In the presence of the colon-specific enzyme azo-reductase (orange), 5-ASA and sulfapyridine are efficiently released.
Publisher: Wiley
Date: 20-04-2018
Abstract: For many regenerative electrochemical energy-conversion systems, hybrid electrocatalysts comprising transition metal (TM) oxides and heteroatom-doped (e.g., nitrogen-doped) carbonaceous materials are promising bifunctional oxygen reduction reaction/oxygen evolution reaction electrocatalysts, whose enhanced electrocatalytic activities are attributed to the synergistic effect originated from the TM-N-C active sites. However, it is still ambiguous which configuration of nitrogen dopants, either pyridinic or pyrrolic N, when bonded to the TM in oxides, predominately contributes to the synergistic effect. Herein, an innovative strategy based on laser irradiation is described to controllably tune the relative concentrations of pyridinic and pyrrolic nitrogen dopants in the hybrid catalyst, i.e., NiCo
Publisher: Wiley
Date: 25-05-2020
Abstract: Electrochemical conversion of CO 2 into ethane is seldom observed because of the generally higher selectivity towards methane, ethylene, and ethanol. Consequently, little experimental evidence for its reaction mechanism exists and thus remains largely unknown. Now, by combining electrochemistry with in situ X‐ray absorption fine‐structure and in situ Raman techniques, iodide‐derived copper (ID‐Cu) and oxide‐derived copper (OD‐Cu) systems were studied to obtain a deeper understanding of the CO 2 to ethane mechanism. With trace iodine species on the surface and positively charged Cu species, production of ethane is significantly more favored on ID‐Cu compared to OD‐Cu, with higher selectivity and faster kinetics. For the first time, it is experimentally found that the formation of ethane follows the same pathway to ethylene and ethanol, and better stabilization of the late stage ethoxy intermediate can steer the reaction to ethane over ethanol.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC10851D
Abstract: Single-crystalline TiOF(2) crystals with cubical morphology were prepared via a facile solvothermal method and their transformation to anatase TiO(2) under different calcination conditions such as pure argon, moist argon and pure hydrogen sulfide (H(2)S) was explored by using XRD/Raman/UV-Vis/SEM/TEM/SAED. The non-metal sulfur doping was successfully fulfilled and the doped TiO(2) microcubes showed the best photocatalytic H(2) evolution property.
Publisher: Springer Science and Business Media LLC
Date: 02-01-2023
Publisher: Elsevier BV
Date: 04-2015
Publisher: Wiley
Date: 30-04-2018
Abstract: The generation of green hydrogen (H
Publisher: American Association for the Advancement of Science (AAAS)
Date: 14-08-2020
Abstract: Visible-light photocatalytic hydrogen is optimized using the synergistic effect of single atoms with their coordinating element.
Publisher: Springer Science and Business Media LLC
Date: 21-01-2023
DOI: 10.1038/S41467-023-35913-6
Abstract: Heteroatom-doping is a practical means to boost RuO 2 for acidic oxygen evolution reaction (OER). However, a major drawback is conventional dopants have static electron redistribution. Here, we report that Re dopants in Re 0.06 Ru 0.94 O 2 undergo a dynamic electron accepting-donating that adaptively boosts activity and stability, which is different from conventional dopants with static dopant electron redistribution. We show Re dopants during OER, (1) accept electrons at the on-site potential to activate Ru site, and (2) donate electrons back at large overpotential and prevent Ru dissolution. We confirm via in situ characterizations and first-principle computation that the dynamic electron-interaction between Re and Ru facilitates the adsorbate evolution mechanism and lowers adsorption energies for oxygen intermediates to boost activity and stability of Re 0.06 Ru 0.94 O 2 . We demonstrate a high mass activity of 500 A g cata. −1 (7811 A g Re-Ru −1 ) and a high stability number of S-number = 4.0 × 10 6 n oxygen n Ru −1 to outperform most electrocatalysts. We conclude that dynamic dopants can be used to boost activity and stability of active sites and therefore guide the design of adaptive electrocatalysts for clean energy conversions.
Publisher: American Chemical Society (ACS)
Date: 18-11-2010
DOI: 10.1021/AM100787W
Abstract: Facile hydrothermal methods have been developed to synthesize large Co3O4 nanocubes, β-Co(OH)2 hexagonal nanodiscs and nanoflowers. S les are thoroughly characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller method, and thermogravimetric analysis. The Co3O4 nanocubes have an average size of about 350 nm with a perfect cubic shape, and the β-Co(OH)2 nanodiscs are uniform hexagonal platelets, whereas the β-Co(OH)2 nanoflowers are assembled from large sheetlike subunits. After thermal annealing in air at a moderate temperature, the as-prepared β-Co(OH)2 s les can be converted into spinel Co3O4 without significant alterations in morphology. We have also investigated the comparative lithium storage properties of these three Co3O4 s les with distinct morphologies. The nanoflower s le shows highly reversible lithium storage capability after 100 charge-discharge cycles.
Publisher: American Chemical Society (ACS)
Date: 10-08-2023
Publisher: Wiley
Date: 17-03-2017
Publisher: Wiley
Date: 16-04-2018
Publisher: American Chemical Society (ACS)
Date: 12-09-2021
DOI: 10.1021/JACS.1C06923
Publisher: Research Square Platform LLC
Date: 12-2020
DOI: 10.21203/RS.3.RS-98178/V1
Abstract: The shuttling of soluble lithium polysulfides between the electrodes leads to serious capacity fading and excess use of electrolyte, which severely bottlenecks practical use of Li-S batteries. Here selective catalysis is proposed as a fundamental remedy for the consecutive solid-liquid-solid sulfur redox reactions. The proof-of-concept In 2 O 3 catalyst targetedly slows down the solid-liquid conversion, dissolution of elemental sulfur to polysulfides, while accelerates the liquid-solid conversion, deposition of polysulfides into insoluble Li 2 S, which basically reduces accumulation of polysulfides in electrolyte, finally inhibiting the shuttle effect. The selective catalysis is revealed, experimentally and theoretically, by changes of activation energies and kinetic currents, modified reaction pathway together with the probed LiInS 2 intermediates, and gradual deactivation of the catalyst. The In 2 O 3 -catalysed Li-S battery works steadily over 1000 cycles at 4.0 C and yields an initial areal capacity up to 9.4 mAh cm −2 with a sulfur loading of ~9.0 mg cm −2 .
Publisher: Wiley
Date: 16-02-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA07271F
Abstract: The integrated dendritic porous yolk@ordered mesoporous shell structured heterogeneous nanocatalysts exhibit enhanced stability and superior catalytic performance.
Publisher: American Chemical Society (ACS)
Date: 08-10-2014
DOI: 10.1021/CM502260M
Publisher: American Chemical Society (ACS)
Date: 10-2014
DOI: 10.1021/CS501124D
Publisher: Elsevier BV
Date: 07-2009
Publisher: Wiley
Date: 20-10-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9EE03549D
Abstract: This review provides enriched information for understanding the charge storage mechanisms of transition metal dichalcogenides (TMDs), as well as the importance of intrinsic structure engineering for enhancing the performance of TMDs in energy storage.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4NR01202J
Abstract: Immunisation studies in mice show that hollow mesoporous silica nanoparticles act as both a delivery vehicle and adjuvant for the viral protein E2 from bovine viral diahorrea virus.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0CC01473G
Abstract: Uniform anatase TiO(2) particles exposed by {001} facets were successfully synthesized by using EDTA together with F as morphology controlling agents. The crystallographic structure as well as the growth mechanism of anatase TiO(2) particles was investigated systematically by XRD, SEM, TEM and XPS, respectively.
Publisher: Research Square Platform LLC
Date: 28-06-2021
DOI: 10.21203/RS.3.RS-390706/V1
Abstract: Background Despite being preventable, suicide is a leading cause of death and a major global public health problem. For every death by suicide, many more suicide attempts are undertaken, and this presents as a critical risk factor for suicide. Currently there are limited treatment options with limited underpinning research for those who present to Emergency Departments with suicidal behaviour. The aim of this study is to assess if adding one of two structured suicide specific psychological interventions (Attempted Suicide Short Intervention Program [ASSIP] or Brief Cognitive Behavioural Therapy [CBT] for Suicide Prevention) to a standardised clinical care approach (Suicide Prevention Pathway [SPP]) improves outcomes for consumers presenting to a Mental Health Service with a suicide attempt. Methods This is a randomised controlled trial with blinding of those assessing the outcomes. People who attempt suicide or experience suicidality after a suicide attempt, present to the Gold Coast Mental Health and Specialist Services, are placed on the Suicide Prevention Pathway (SPP) and meet the eligibility criteria, are offered the opportunity to participate. A total of 411 participants will be recruited for the study, with 137 allocated to each cohort (participants are randomised to SPP, ASSIP + SPP, or CBT + SPP). The primary outcomes of this study are re-presentation to hospital with suicide attempt and/or suicidal ideations. Death by suicide rates will also be examined. Self-reported level of suicidality, depression, anxiety, stress, resilience, problem-solving skills, self- and therapist-reported level of therapeutic engagement are also being examined. Psychometric data are collected at baseline, end of interventions, 6,12, and 24 months. Discussion This project will move both ASSIP and Brief CBT from efficacy to effectiveness research, with clear aims of assessing the addition of two structured psychological interventions to treatment as usual, providing a cost-benefit analysis of the interventions, thus delivering outcomes providing a clear pathway for rapid translation of successful interventions. Trials registration : NCT04072666 - Registered on 28th August 2019 on Clinical Trials US Gov (t2/show/NCT04072666?term=NCT04072666& draw=2& rank=1) and ANZCTR (www.anzctr.org.au/TrialSearch.aspx)
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR03869G
Abstract: A smart drug delivery system with non-destructive surface-enhanced Raman scattering tracing tags and targeted cancer-cell cytotoxicities is constructed.
Publisher: Wiley
Date: 30-11-2016
Abstract: In spite of recent advances in the synthesis of hollow micro/nanostructures, the fabrication of three-dimensional electrodes on the basis of these structures remains a major challenge. Herein, we develop an electrochemical sacrificial-template strategy to fabricate hollow Co
Publisher: Elsevier BV
Date: 06-2018
Publisher: Wiley
Date: 24-08-2010
Abstract: CdSe colloidal nanowires, generated from solution‐liquid‐solid approach, have been coated with CdS rods (or ribbons) by using cadmium hexadecyl xanthate (Cd‐HDX) as a single source precursor. The use of different solvents and ligands causes pronounced effects on the morphology of the nanowires. The coating process includes nucleation and growth of CdS nanorods onto the core CdSe nanowires, followed by ripening of the CdS nanorods to produce the desired core‐shell nanowire structure.
Publisher: Wiley
Date: 10-06-2018
Publisher: Wiley
Date: 24-11-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA00967A
Abstract: Dual-shell structured sodium titanate cubes with oxygen vacancies are rationally designed and synthesized. Various state-of-the-art approaches offer understandings of its enhanced ion kinetics as an anode for sodium-ion battery..
Publisher: Wiley
Date: 19-12-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6QM00241B
Abstract: A metal-free ternary homo-heterojunction is developed for the first time and demonstrated for enhanced photocatalytic hydrogen production.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7TA08115D
Abstract: Layered transition metal disulfides are currently being widely studied for advanced energy generation and storage applications.
Publisher: Elsevier
Date: 2007
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR01170A
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5TA08988C
Abstract: Mesocrystalline cupric oxide with pure phase and clean surface was produced by laser ablation followed by oxidation, and a gas sensor based on the mesocrystal exhibits the highest sensitivity, the fastest response, and the best selectivity ever reported towards ethanol.
Publisher: Elsevier BV
Date: 09-2019
Publisher: American Chemical Society (ACS)
Date: 28-08-2021
Publisher: Wiley
Date: 14-07-2015
Abstract: Over the past decade, developing advanced catalysts for clean and sustainable energy conversion has been subject to extensive study. Driven by great advances achieved in computational quantum chemistry, synthetic chemistry, and material characterization techniques, the preferential design of a most-appropriate catalyst for a specific electrochemical reaction is possible. Here a universal process for the design of high-performance carbon-based electrocatalysts, by engineering their intrinsic electronic structures and physical structures to promote their extrinsic activities for different energy conversion reactions, is presented and summarized. How such a powerful strategy may aid the discovery of more electrocatalysts for a sustainable and clean energy infrastructure is discussed.
Publisher: Elsevier BV
Date: 10-2008
Publisher: Elsevier BV
Date: 06-2016
Publisher: Wiley
Date: 18-01-2021
Publisher: Wiley
Date: 15-08-2012
Abstract: Replacing precious and nondurable Pt catalysts with cheap and commercially available materials to facilitate sluggish cathodic oxygen reduction reaction (ORR) is a key issue in the development of fuel cell technology. The recently developed cost effective and highly stable metal-free catalysts reveal comparable catalytic activity and significantly better fuel tolerance than that of current Pt-based catalysts therefore, they can serve as feasible Pt alternatives for the next generation of ORR electrocatalysts. Their promising electrocatalytic properties and acceptable costs greatly promote the R&D of fuel cell technology. This review provides an overview of recent advances in state-of-the-art nanostructured metal-free electrocatalysts including nitrogen-doped carbons, graphitic-carbon nitride (g-C(3) N(4) )-based hybrids, and 2D graphene-based materials. A special emphasis is placed on the molecular design of these electrocatalysts, origin of their electrochemical reactivity, and ORR pathways. Finally, some perspectives are highlighted on the development of more efficient ORR electrocatalysts featuring high stability, low cost, and enhanced performance, which are the key factors to accelerate the commercialization of fuel cell technology.
Publisher: Public Library of Science (PLoS)
Date: 04-11-2015
Publisher: Springer Science and Business Media LLC
Date: 10-12-2021
DOI: 10.1038/S41467-021-27551-7
Abstract: Metal sulfides electrodeposition in sulfur cathodes mitigates the shuttle effect of polysulfides to achieve high Coulombic efficiency in secondary metal-sulfur batteries. However, fundamental understanding of metal sulfides electrodeposition and kinetics mechanism remains limited. Here using room-temperature sodium-sulfur cells as a model system, we report a Mo 5 N 6 cathode material that enables efficient Na 2 S electrodeposition to achieve an initial discharge capacity of 512 mAh g −1 at a specific current of 1 675 mA g −1 , and a final discharge capacity of 186 mAh g −1 after 10,000 cycles. Combined analyses from synchrotron-based spectroscopic characterizations, electrochemical kinetics measurements and density functional theory computations confirm that the high d -band position results in a low Na 2 S 2 dissociation free energy for Mo 5 N 6 . This promotes Na 2 S electrodeposition, and thereby favours long-term cell cycling performance.
Publisher: Wiley
Date: 04-2016
Abstract: Strongly coupled Nafion molecules and ordered porous CdS networks are fabricated for visible-light photoelectrochemical (PEC) hydrogen evolution. The Nafion layer coating shifts the band position of CdS upward and accelerates charge transfer in the photoelectrode/electrolyte interface. It is highly expected that the strong coupling effect between organic and inorganic materials will provide new routes to advance PEC water splitting.
Publisher: Wiley
Date: 08-01-2018
Abstract: Ever-increasing fossil-fuel combustion along with massive CO
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6TA10733H
Abstract: Grain boundaries on the Au(110) surface facilitate the production of liquid fuel CH 3 OH for CO 2 electroreduction by strongly binding the CO intermediate.
Publisher: Wiley
Date: 09-2000
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA43382J
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2EE03479D
Publisher: Wiley
Date: 18-11-2020
Abstract: The oule method provides a promising pathway towards the controllable synthesis of novel electrocatalysts for water electrolysis due to its straightforward manipulation of reaction conditions, accessible experimental design, and controlled environment. This Concept introduces the development of the oule method and anticipates its application in electrocatalyst synthesis for water electrolysis. First, the history, device configuration, and merits of the oule method are briefly introduced. Afterwards, typical materials synthesized by the oule method are discussed. Then, recent process in applying the oule method to synthesize electrocatalysts for water electrolysis is highlighted. Finally, opportunities and potentials of this method in facilitating electrocatalyst synthesis for water electrolysis are discussed.
Publisher: American Chemical Society (ACS)
Date: 12-10-2018
Publisher: Wiley
Date: 17-09-2013
Abstract: Copper modification is an efficient way to enhance the photocatalytic activity of ZnS-based materials however, the mechanisms of Cu(2+) surface and bulk modifications for improving the activity are quite different. In this work, two different synthetic pathways were devised to prepare surface and bulk Cu(2+)-modified Znx Cd1-x S photocatalysts through cation-exchange and coprecipitation methods, respectively. Different Cu(2+) modifications brought different effects on the phase structure, morphology, surface area, optical property, as well as the photocatalytic H2-production activity of the final products. The optimized Cu(2+)-surface-modified Znx Cd1-x S photocatalyst has a high H2-production rate of 4638.5 μmolh(-1) g(-1) and an apparent quantum efficiency of 20.9% at 420 nm, exceeding that of Cu(2+)-bulk-modified catalyst at the same copper content. Cu(2+) surface modification not only brings a new electron-transferring pathway (interfacial charge transfer), but also produces new surface active sites for H2 evolution, reducing the recombination rate of photogenerated charge carriers.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1SC01694F
Abstract: Densely-arrayed Cu nanopyramids have spatial confinement induced by the additional Cu–O bond. This promotes C–C coupling, regulates post-C–C coupling, and retains both oxygen atoms in an alternative pathway toward ethylene glycol formation from CO.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR03089G
Abstract: Composite materials combining nitrogen-doped carbon (NC) with active species represent a paramount breakthrough as alternative catalysts to Pt for the oxygen reduction reaction (ORR) due to their competitive activity, low cost and excellent stability. In this paper, a simple strategy is presented to construct graphene oxide-polydopamine (GD) based carbon nanosheets. This approach does not need to modify graphene and use any catalyst for polymerization under ambient conditions, and the obtained carbon nanosheets possess adjustable thicknesses and uniform mesoporous structures without using any template. The thickness of GD hybrids and the carbonization temperature are found to play crucial roles in adjusting the microstructure of the resulting carbon nanosheets and, accordingly their ORR catalytic activity. The optimized carbon nanosheet generated by a GD hybrid of 5 nm thickness after 900 °C carbonization exhibits superior ORR activity with an onset potential of -0.07 V and a kinetic current density of 13.7 mA cm(-2) at -0.6 V. The unique mesoporous structure, high surface areas, abundant defects and favorable nitrogen species are believed to significantly benefit the ORR catalytic process. Furthermore, it also shows remarkable durability and excellent methanol tolerance outperforming those of commercial Pt/C. In view of the physicochemical versatility and structural tunability of polydopamine (PDA) materials, our work would shed new light on the understanding and further development of PDA-based carbon materials for highly efficient electrocatalysts.
Publisher: Wiley
Date: 27-11-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1EE00740H
Abstract: The review presents the important role of oxygen-bound intermediates in directing the selectivity of electrochemical CO 2 reduction by considering available theoretical calculations, electrochemical measurements and operando spectroscopy observations.
Publisher: American Chemical Society (ACS)
Date: 21-06-2023
DOI: 10.1021/JACS.3C03022
Publisher: American Association for the Advancement of Science (AAAS)
Date: 20-10-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C8NR09680E
Abstract: Ni-BDC/Ni(OH) 2 hybrid nanosheets were fabricated and explored as a highly efficient electrocatalyst for the oxygen evolution reaction.
Publisher: Elsevier BV
Date: 02-2019
Publisher: Springer Science and Business Media LLC
Date: 09-2014
Publisher: American Chemical Society (ACS)
Date: 12-01-2021
Publisher: IOP Publishing
Date: 11-01-2010
DOI: 10.1088/0957-4484/21/6/065604
Abstract: 1D hierarchical composite mesostructures of titanate and silica were synthesized via an interfacial surfactant templating approach. Such mesostructures have complex core-shell architectures consisting of single-crystalline H(2)Ti(3)O(7) nanobelts inside the ordered mesoporous SiO(2) shell, which are nontoxic and highly biocompatible. The overall diameter of as-prepared 1D hierarchical composite mesostructures is only approx. 34.2 nm with a length over 500 nm on average. A model to explain the formation mechanism of these mesostructures has been proposed the negatively charged surface of H(2)Ti(3)O(7) nanobelts controls the formation of the octadecyltrimethylammonium bromide (C(18)TAB) bilayer, which in turn regulates the cooperative self-assembly of silica and C(18)TAB complex micelles on the interface to produce a mesoporous silica shell. More importantly, the application of synthesized mesostructured nanocables as anticancer drug reservoirs has also been explored, which indicates that the membranes containing these mesoporous nanocables have a great potential to be used as transdermal drug delivery systems.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 22-05-2020
Abstract: Aqueous batteries are a reliable alternative for next-generation safe, low-cost, and scalable energy storage.
Publisher: Wiley
Date: 07-07-2021
Abstract: Monitoring and controlling the reconstruction of materials under working conditions is crucial for the precise identification of active sites, elucidation of reaction mechanisms, and rational design of advanced catalysts. Herein, a Bi‐based metal–organic framework (Bi‐MOF) for electrochemical CO 2 reduction is selected as a case study. In situ Raman spectra combined with ex situ electron microscopy reveal that the intricate reconstruction of the Bi‐MOF can be controlled using two steps: 1) electrolyte‐mediated dissociation and conversion of Bi‐MOF to Bi 2 O 2 CO 3 , and 2) potential‐mediated reduction of Bi 2 O 2 CO 3 to Bi. The intentionally reconstructed Bi catalyst exhibits excellent activity, selectivity, and durability for formate production, and the unsaturated surface Bi atoms formed during reconstruction become the active sites. This work emphasizes the significant impact of pre‐catalyst reconstruction under working conditions and provides insight into the design of highly active and stable electrocatalysts through the regulation of these processes.
Publisher: Wiley
Date: 03-05-2022
Abstract: Electrocatalysts for high-rate hydrogen evolution reaction (HER) are crucial to clean fuel production. Nitrogen-rich 2D transition metal nitride, designated "nitridene", has shown promising HER performance because of its unique physical/chemical properties. However, its synthesis is hindered by the sluggish growth kinetics. Here for the first time using a catalytic molten-salt method, we facilely synthesized a V-Mo bimetallic nitridene solid solution, V
Publisher: American Chemical Society (ACS)
Date: 12-02-2010
DOI: 10.1021/IE901469C
Publisher: Wiley
Date: 25-02-2020
Abstract: Vacancy engineering is an effective strategy to manipulate the electronic structure of electrocatalysts to improve their performance, but few reports focus on phosphorus vacancies (Pv). Herein, the creation of Pv in metal phosphides and investigation of their role in alkaline electrocatalytic hydrogen evolution reaction (HER) is presented. The Pv-modified catalyst requires a minimum onset potential of 0 mV vs. RHE, a small overpotential of 27.7 mV to achieve 10 mA cm
Publisher: Elsevier BV
Date: 07-2012
Publisher: Wiley
Date: 20-10-2021
Abstract: Aqueous Zn‐ion batteries (ZIBs) are regarded as alternatives to Li‐ion batteries benefiting from both improved safety and environmental impact. The widespread application of ZIBs, however, is compromised by the lack of high‐performance cathodes. Currently, only the intercalation mechanism is widely reported in aqueous ZIBs, which significantly limits cathode options. Beyond Zn‐ion intercalation, we comprehensively study the conversion mechanism for Zn 2+ storage and its diffusion pathway in a CuI cathode, indicating that CuI occurs a direct conversion reaction without Zn 2+ intercalation due to the high energy barrier for Zn 2+ intercalation and migration. Importantly, this direct conversion reaction mechanism can be readily generalized to other high‐capacity cathodes, such as Cu 2 S (336.7 mA h g −1 ) and Cu 2 O (374.5 mA h g −1 ), indicating its practical universality. Our work enriches the Zn‐ion storage mechanism and significantly broadens the cathode horizons towards next‐generation ZIBs.
Publisher: Elsevier BV
Date: 04-2011
Publisher: Elsevier BV
Date: 09-2020
Publisher: Wiley
Date: 19-07-2017
Publisher: Elsevier BV
Date: 04-2011
Publisher: Wiley
Date: 27-10-2022
Abstract: Single‐atom catalysts (SACs) hold great promise for highly efficient heterogeneous catalysis, yet the practical applications require the development of high‐density active sites with flexible geometric structures. The lack of understanding in the dynamic formation process of single atoms in the host framework has been plaguing the controllable synthesis of next generation SACs. Here using Co‐based metal‐organic frameworks (MOFs) as a starting substrate, we fully elucidated the formation of high‐density Pt single atoms with inter‐site interactions in derived Co 3 O 4 host. The cation exchange process and dynamic evolution of Pt−Pt interactions, organic ligand cleavage and Pt‐oxygen coordination formation during the pyrolysis process have been unambiguously interpreted by a series of in situ/ex situ spectroscopic measurements and theoretical computation. These findings would direct the synthesis of high‐density SACs with metal‐metal interactions, which demonstrate significantly enhanced structural flexibility and catalytic properties.
Publisher: Wiley
Date: 02-10-2013
Abstract: A new strategy for promoting endoplasmic gene delivery and nucleus uptake is proposed by developing intracellular microenvironment responsive biocompatible polymers. This delivery system can efficiently load and self-assemble nucleic acids into nano-structured polyplexes at a neutral pH, release smaller imidazole-gene complexes from the polymer backbones at intracellular endosomal pH, transport nucleic acids into nucleus through intracellular environment responsive multiple-stage gene delivery, thus leading to a high cell transfection efficiency.
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.BIOMATERIALS.2016.03.019
Abstract: Mesoporous silica material with organo-bridged silsesquioxane frameworks is a kind of synergistic combination of inorganic silica, mesopores and organics, resulting in some novel or enhanced physicochemical and biocompatible properties compared with conventional mesoporous silica materials with pure Si-O composition. With the rapid development of nanotechnology, monodispersed nanoscale periodic mesoporous organosilica nanoparticles (PMO NPs) and organo-bridged mesoporous silica nanoparticles (MSNs) with various organic groups and structures have recently been synthesized from 100%, or less, bridged organosilica precursors, respectively. Since then, these materials have been employed as carrier platforms to construct bioimaging and/or therapeutic agent delivery nanosystems for nano-biomedical application, and they demonstrate some unique and/or enhanced properties and performances. This review article provides a comprehensive overview of the controlled synthesis of PMO NPs and organo-bridged MSNs, physicochemical and biocompatible properties, and their nano-biomedical application as bioimaging agent and/or therapeutic agent delivery system.
Publisher: Wiley
Date: 26-04-2013
Abstract: Immunization to the model protein antigen ovalbumin (OVA) is investigated using MCM-41 mesoporous silica nanoparticles as a novel vaccine delivery vehicle and adjuvant system in mice. The effects of amino surface functionalization and adsorption time on OVA adsorption to nanoparticles are assessed. Amino-functionalized MCM-41 (AM-41) shows an effect on the amount of OVA binding, with 2.5-fold increase in binding capacity (72 mg OVA/g AM-41) compared to nonfunctionalized MCM-41 (29 mg OVA/g MCM-41). Immunization studies in mice with a 10 μg dose of OVA adsorbed to AM-41 elicits both antibody and cell-mediated immune responses following three subcutaneous injections. Immunizations at a lower 2 μg dose of OVA adsorbed to AM-41 particles results in an antibody response but not cell-mediated immunity. The level of antibody responses following immunization with nanoformulations containing either 2 μg or 10 μg of OVA are only slightly lower than that in mice which receive 50 μg OVA adjuvanted with QuilA, a crude mixture of saponins extracted from the bark of the Quillaja saponaria Molina tree. This is a significant result, since it demonstrates that AM-41 nanoparticles are self-adjuvanting and elicit immune responses at reduced antigen doses in vivo compared to a conventional delivery system. Importantly, there are no local or systemic negative effects in animals injected with AM-41. Histopathological studies of a range of tissue organs show no changes in histopathology of the animals receiving nanoparticles over a six week period. These results establish the biocompatible MCM-41 silica nanoparticles as a new method for vaccine delivery which incorporates a self-adjuvant effect.
Publisher: American Chemical Society (ACS)
Date: 29-11-2011
DOI: 10.1021/JA209206C
Abstract: Based on theoretical prediction, a g-C(3)N(4)@carbon metal-free oxygen reduction reaction (ORR) electrocatalyst was designed and synthesized by uniform incorporation of g-C(3)N(4) into a mesoporous carbon to enhance the electron transfer efficiency of g-C(3)N(4). The resulting g-C(3)N(4)@carbon composite exhibited competitive catalytic activity (11.3 mA cm(-2) kinetic-limiting current density at -0.6 V) and superior methanol tolerance compared to a commercial Pt/C catalyst. Furthermore, it demonstrated significantly higher catalytic efficiency (nearly 100% of four-electron ORR process selectivity) than a Pt/C catalyst. The proposed synthesis route is facile and low-cost, providing a feasible method for the development of highly efficient electrocatalysts.
Publisher: American Chemical Society (ACS)
Date: 03-06-2014
DOI: 10.1021/NN501506P
Abstract: Active sites and the catalytic mechanism of nitrogen-doped graphene in an oxygen reduction reaction (ORR) have been extensively studied but are still inconclusive, partly due to the lack of an experimental method that can detect the active sites. It is proposed in this report that the active sites on nitrogen-doped graphene can be determined via the examination of its chemical composition change before and after ORR. Synchrotron-based X-ray photoelectron spectroscopy analyses of three nitrogen-doped multilayer graphene s les reveal that oxygen reduction intermediate OH(ads), which should chemically attach to the active sites, remains on the carbon atoms neighboring pyridinic nitrogen after ORR. In addition, a high amount of the OH(ads) attachment after ORR corresponds to a high catalytic efficiency and vice versa. These pinpoint that the carbon atoms close to pyridinic nitrogen are the main active sites among the different nitrogen doping configurations.
Publisher: Wiley
Date: 16-07-2021
Abstract: Owing to dwindling fossil fuels reserves, the development of alternative renewable energy sources is globally important. Photocatalytic hydrogen (H 2 ) evolution represents a practical and affordable alternative to convert sunlight into carbon‐free H 2 fuel. Recently, 2D/2D van der Waals heterostructures (vdWHs) have attracted significant research attention for photocatalysis. Here, for the first time a ReS 2 /In 2 ZnS 4 2D/2D vdWH synthesized via a facile physical mixing is reported. It exhibits a highly promoted photocatalytic H 2 ‐evolution rate of 2515 µmol h −1 g −1 . Importantly, this exceeds that for pristine In 2 ZnS 4 by about 22.66 times. This, therefore, makes ReS 2 /In 2 ZnS 4 one of the most efficient In 2 ZnS 4 ‐based photocatalysts without noble‐metal cocatalysts. Advanced characterizations and theoretical computations results show that interlayer electronic interaction within ReS 2 /In 2 ZnS 4 vdWH and atomic‐level S active centers along the edges of ReS 2 NSs work collaboratively to result in the boosted light‐induced H 2 evolution. Results will be of immediate benefit in the rational design and preparation of vdWHs for applications in catalysis/(opto)electronics.
Publisher: Elsevier BV
Date: 12-2009
Publisher: American Chemical Society (ACS)
Date: 27-02-2009
DOI: 10.1021/JA808790P
Abstract: Owing to wide-ranging industrial applications and fundamental importance, tailored synthesis of well-faceted single crystals of anatase TiO(2) with high percentage of reactive facets has attracted much research interest. In this work, high-quality anatase TiO(2) single-crystal nanosheets mainly dominated by {001} facets have been prepared by using a water-2-propanol solvothermal synthetic route. The synergistic functions of 2-propanol and HF on the growth of anatase TiO(2) single-crystal nanosheets were studied by first-principle theoretical calculations, revealing that the addition of 2-propanol can strengthen the stabilization effect associated with fluorine adsorption over (001) surface and thus stimulate its preferred growth. By measuring the (*)OH species with terephthalic acid scavenger, the as-prepared anatase TiO(2) single-crystal nanosheets having 64% {001} facets show superior photoreactivity (more than 5 times), compared to P25 as a benchmarking material.
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 02-2019
Publisher: MDPI AG
Date: 08-03-2021
DOI: 10.3390/JMSE9030295
Abstract: Barrier islands (BIs) are the first line of defense against the sea/wave actions in coastal areas, and assessing their stability is crucial in the context of effective coastal planning. Therefore, this study evaluates the spatial–temporal shoreline changes of the BIs in Pakistan over the past three decades (1989–2018). Satellite data from Landsat missions are used to delineate the shorelines of 19 BIs in Pakistan. After delineating the shorelines from satellite observations, two well-known statistical methods (i.e., end point rate (EPR) and linear regression rate (LRR)) are used to capture the localized changes in the BIs. The results ascertain that nearly all of the BIs have experienced noteworthy erosion during the past three decades. While the mean erosion over all the BIs during the study period is estimated to be m/y, significant spatial heterogeneities among the in idual BIs exist. The interdecadal comparison indicates that the highest mean erosion of the BIs occurred during the period 1989–1999 (13.03 ± 0.62 m/y), which gradually reduced over the preceding decades (i.e., 7.76 ± 0.62 m/y during the period 1999–2009 and 3.8 ± 0.7 m/y during the period 2009–2018). Nevertheless, ~65% of the total BIs experienced high erosion ( m/y), ~15% experienced moderate ( m/y), and ~20% experienced low erosion ( m/y) during the period 1989-2018. This situation implies that while ~65% of these BIs need immediate interventions from the concerned authorities, the 15% BIs with moderate erosion might experience high erosion in the wake of rising sea levels and decreasing sediment influx in the near future without proper measures. This depletion of the BIs might not only affect Pakistan but also have regional consequences due to their various services.
Publisher: Elsevier BV
Date: 2013
Publisher: Wiley
Date: 10-10-2012
Publisher: Wiley
Date: 04-11-2013
Publisher: Wiley
Date: 25-08-2021
Abstract: Practical application of aqueous Zn‐ion batteries (AZIBs) is significantly limited by poor reversibility of the Zn anode. This is because of 1) dendrite growth, and 2) water‐induced parasitic reactions including hydrogen evolution, during cycling. Here for the first time an elegantly simple method is reported that introduces ethylene diamine tetraacetic acid tetrasodium salt (Na 4 EDTA) to a ZnSO 4 electrolyte. This is shown to concomitantly suppress dendritic Zn deposition and H 2 evolution. Findings confirm that EDTA anions are adsorbed on the Zn surface and dominate active sites for H 2 generation and inhibit water electrolysis. Additionally, adsorbed EDTA promotes desolvation of Zn(H 2 O) 6 2+ by removing H 2 O molecules from the solvation sheath of Zn 2+ . Side reactions and dendrite growth are therefore suppressed by using the additive. A high Zn reversibility with Coulombic efficiency (CE) of 99.5% and long lifespan of 2500 cycles at 5 mAh cm −2 , 2 mAh cm −2 is demonstrated. Additionally, the highly reversible Zn electrode significantly boosts overall performance of VO 2 //Zn full‐cells. These findings are expected to be of immediate benefit to a range of researchers in using dual‐function additives to suppress Zn dendrite and parasitic reactions for electrochemistry and energy storage applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA01932D
Abstract: The direct conversion of CO 2 to syngas with controllable composition remains an intense interest for the production of renewable fuels.
Publisher: American Chemical Society (ACS)
Date: 16-02-2017
DOI: 10.1021/ACS.ACCOUNTS.6B00635
Abstract: Developing cost-effective and high-performance electrocatalysts for renewable energy conversion and storage is motivated by increasing concerns regarding global energy security and creating sustainable technologies dependent on inexpensive and abundant resources. Recent achievements in the design and synthesis of efficient non-precious-metal and even non-metal electrocatalysts make the replacement of noble metal counterparts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) with earth-abundant elements, for ex le, C, N, Fe, Mn, and Co, a realistic possibility. It has been found that surface atomic engineering (e.g., heteroatom-doping) and interface atomic or molecular engineering (e.g., interfacial bonding) can induce novel physicochemical properties and strong synergistic effects for electrocatalysts, providing new and efficient strategies to greatly enhance the catalytic activities. In this Account, we discuss recent progress in the design and fabrication of efficient electrocatalysts based on carbon materials, graphitic carbon nitride, and transition metal oxides or hydroxides for efficient ORR, OER, and HER through surface and interfacial atomic and molecular engineering. Atomic and molecular engineering of carbon materials through heteroatom doping with one or more elements of noticeably different electronegativities can maximally tailor their electronic structures and induce a synergistic effect to increase electrochemical activity. Nonetheless, the electrocatalytic performance of chemically modified carbonaceous materials remains inferior to that of their metallic counterparts, which is mainly due to the relatively limited amount of electrocatalytic active sites induced by heteroatom doping. Accordingly, coupling carbon substrates with other active electrocatalysts to produce composite structures can impart novel physicochemical properties, thereby boosting the electroactivity even further. Although the majority of carbon-based materials remain uncompetitive with state-of-the-art metal-based catalysts for the aforementioned catalytic processes, non-metal carbon hybrids have already shown performance that typically only conventional noble metals or transition metal materials can achieve. The idea of hybridized carbon-based catalysts possessing unique active surfaces and macro- or nanostructures is addressed herein. For metal-carbon couples, the incorporation of carbon can effectively compensate for the intrinsic deficiency in conductivity of the metallic components. Chemical modification of carbon frameworks, such as nitrogen doping, not only can change the electron-donor character, but also can introduce anchoring sites for immobilizing active metallic centers to form metal-nitrogen-carbon (M-N-C) species, which are thought to facilitate the electrocatalytic process. With thoughtful material design, control over the porosity of composites, the molecular architecture of active metal moieties and macromorphologies of the whole catalysts can be achieved, leading to a better understanding structure-activity relationships. We hope that we can offer new insight into material design, particularly the role of chemical composition and structural properties in electrochemical performance and reaction mechanisms.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1CC03796J
Abstract: The OC–COH coupling is kinetically facilitated compared to OC–CHO coupling, which is induced by the optimized composition and electronic structures of copper alloys.
Publisher: Wiley
Date: 17-12-2014
Abstract: Flexible non-metal oxygen electrodes fabricated from phosphorus-doped graphitic carbon nitride nano-flowers directly grown on carbon-fiber paper exhibit high activity and stability in reversibly catalyzing oxygen reduction and evolution reactions, which is a result of N, P dual action, enhanced mass/charge transfer, and high active surface area. The performance is comparable to that of the state-of-the-art transition-metal, noble-metal, and non-metal catalysts. Remarkably, the flexible nature of these oxygen electrodes allows their use in folded and rolled-up forms, and directly as cathodes in Zn-air batteries, featuring low charge/discharge overpotential and long lifetime.
Publisher: Wiley
Date: 14-09-2010
Publisher: Wiley
Date: 06-2016
Abstract: Replacement of precious metal electrocatalysts with highly active and cost efficient alternatives for complete water splitting at low voltage has attracted a growing attention in recent years. Here, this study reports a carbon-based composite co-doped with nitrogen and trace amount of metallic cobalt (1 at%) as a bifunctional electrocatalyst for water splitting at low overpotential and high current density. An excellent electrochemical activity of the newly developed electrocatalyst originates from its graphitic nanostructure and highly active Co-Nx sites. In the case of carefully optimized s le of this electrocatalyst, 10 mA cm(-2) current density can be achieved for two half reactions in alkaline solutions-hydrogen evolution reaction and oxygen evolution reaction-at low overpotentials of 220 and 350 mV, respectively, which are smaller than those previously reported for nonprecious metal and metal-free counterparts. Based on the spectroscopic and electrochemical investigations, the newly identified Co-Nx sites in the carbon framework are responsible for high electrocatalytic activity of the Co,N-doped carbon. This study indicates that a trace level of the introduced Co into N-doped carbon can significantly enhance its electrocatalytic activity toward water splitting.
Publisher: Wiley
Date: 13-10-2020
Publisher: Elsevier BV
Date: 04-2011
Publisher: Elsevier BV
Date: 02-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7EE02220D
Abstract: This perspective highlights the rational design of efficient electrocatalysts and photo(electro)catalysts for N 2 reduction to ammonia (NH 3 ) under ambient conditions.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC13929K
Abstract: We demonstrate an unusual formation of large 2D nanosheets from nanomosaic building blocks of anatase TiO(2) nanosheets with exposed (001) facets. It is proposed that large PVP molecules adsorbed on the (001) facets serve as the linker that brings building blocks together, at the same time prevents them from stacking along the c-axis.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC06378D
Abstract: A two-dimensional metal–organic framework comprising nickel species and an organic ligand of benzenedicarboxylic acid is fabricated and explored as an electrocatalyst for urea oxidation reaction.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0TA11201A
Abstract: This perspective summarizes the design and synthesis of two-dimensional building block based photocatalysts for light-induced NH 3 production. The structure–performance relationship and mechanism of photocatalysts are highlighted.
Publisher: Wiley
Date: 06-10-2014
Publisher: American Chemical Society (ACS)
Date: 09-11-2010
DOI: 10.1021/ES102884V
Abstract: Heavy metal ions (Ni(2+), Zn(2+), and Cr(3+)) can be effectively removed from real polynary metal ions-bearing electroplating wastewaters by a carbonation process, with ∼99% of metal ions removed in most cases. The synchronous formation of layered double hydroxide (LDH) precipitates containing these metal ions was responsible for the self-purification of wastewaters. The constituents of formed polynary metals-LDHs mainly depended on the Ni(2+):Zn(2+):Cr(3+) molar ratio in wastewaters. LDH was formed at pH of 6.0-8.0 when the Ni(2+)/Zn(2+) molar ratio ≥ 1 where molar fraction of trivalent metal in the wastewaters was 0.2-0.4, otherwise ZnO, hydrozincite, or amorphous precipitate was observed. In the case of LDH formation, the residual concentration of Ni(2+), Zn(2+), and Cr(3+) in the treated wastewaters was very low, about 2-3, ∼2, and ∼1 mg/L, respectively, at 20-80 °C and pH of 6.0-8.0, indicating the effective incorporation of heavy metal ions into the LDH matrix. Furthermore, the obtained LDH materials were used to adsorb azoic dye GR, with the maximum adsorption amount of 129-134 mg/g. We also found that the obtained LDHs catalyzed more than 65% toluene to decompose at 350 °C under ambient pressure. Thus the current research has not only shown effective recovery of heavy metal ions from the electroplating wastewaters in an environmentally friendly process but also demonstrated the potential utilization of recovered materials.
Publisher: Trans Tech Publications, Ltd.
Date: 03-2007
DOI: 10.4028/WWW.SCIENTIFIC.NET/SSP.121-123.381
Abstract: Highly ordered rods of large-pore periodic mesoporous organosilica (PMO) were successfully synthesized at low acid concentrations and in the presence of inorganic salt using triblock copolymer P123 as template. The roles of inorganic salt, acidity and temperature in the production of highly ordered mesostructure and the morphology control of PMOs were examined and elucidated. It was found that the addition of inorganic salt can dramatically widen the range of the synthesis parameters to produce highly ordered 2D hexagonal pore structure of p6mm symmetry. However, the uniform rods of PMOs can only be synthesized in a narrow range of acid and salt concentrations, which was sensitive to induction time. The results also showed that the optimized salt concentration (1 M) and low acidity (0.167 M) at 40 oC were beneficial to not only the production of highly ordered mesostucture but also the control of rod-like morphology. Highly ordered rods can also be produced at low temperature (35 oC) with high salt amount (1.5 M) or high temperature (45 oC) with low salt concentration (0.5 M).
Publisher: American Chemical Society (ACS)
Date: 21-06-2016
Publisher: American Chemical Society (ACS)
Date: 18-08-2014
DOI: 10.1021/AM5041219
Abstract: Three-dimensional (3D) heterojunction solar cells (HSCs) were fabricated by thermal deposition of a compact CdTe layer onto ZnO nanorods (NRs). Although the 3D architecture obviously improves the short-circuit current of HSCs, the open-circuit voltage is rather low, and this problem can be addressed by inserting an intermediate layer between ZnO NRs and the CdTe layer. On the basis of experimental and theoretical analyses, we found that the low open-circuit voltage mainly arose from the incomplete depletion layer and serious recombination of carriers at the CdTe/ZnO interface. The CdS intermediate layer can redistribute the depletion regions and eliminate the interface defects, thus remarkably improving the open-circuit voltage.
Publisher: Wiley
Date: 20-04-2023
Abstract: Improving kinetics of solid‐state sulfide conversion in sulfur cathodes can enhance sulfur utilization of metal‐sulfur batteries. However, fundamental understanding of the solid‐state conversion remains to be achieved. Here, taking potassium‐sulfur batteries as a model system, we for the first time report the reducing overpotential of solid‐state sulfide conversion via the meta‐stable S 3 2− intermediates on transition metal single‐atom sulfur hosts. The catalytic sulfur host containing Cu single atoms demonstrates high capacities of 1595 and 1226 mAh g −1 at current densities of 335 and 1675 mA g −1 , respectively, with stable Coulombic efficiency of ≈100 %. Combined spectroscopic characterizations and theoretical computations reveal that the relatively weak Cu‐S bonding results in low overpotential of solid‐state sulfide conversion and high sulfur utilization. The elucidation of solid‐state sulfide conversion mechanism can direct the exploration of highly efficient metal‐sulfur batteries.
Publisher: Wiley
Date: 02-01-2019
Publisher: Wiley
Date: 29-12-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA12347B
Publisher: Wiley
Date: 08-12-2008
Publisher: MDPI AG
Date: 25-04-2022
DOI: 10.3390/RS14092054
Abstract: This study employed remote sensing (optical and synthetic aperture radar) and data analysis techniques to quantify vertical ground displacements and assess their contribution to coastline erosion. To provide evidence from Pakistan, we selected the coast of Karachi—a mega-city located along the dynamic coastline of the Indus River Delta—which has been experiencing severe coastal erosion during the last few decades. Observations from the C-band Envisat/ASAR and Sentinel-1A sensors over the 2004–2010 and 2014–2016 periods, respectively, enabled us to study vertical ground displacements in the study area, providing a long-term assessment during 2004–2016. Results suggest that some areas along the Karachi coastline are subsiding at comparable rates to or even much higher than the relative sea-level rise (SLR, ~1.9 mm/yr), which may lify the rates of relative SLR in coming years, along with accelerating coastal erosion. Various parts of the study area along the coast are unstable and undergoing displacement. Landsat images from 1989 to 2018 (10-year temporal resolution) were further used to examine the state of coastline erosion using three statistical approaches (i.e., End Point Rate (EPR), Linear Regression Rate (LRR), and Least Median of Squares (LMS)). While the erosion underlaid the majority of the eastern sections of the study area, the ground displacements were spatially heterogeneous across the study area and along the coastline. Erosion rates of ~2.4 m/yr spatially corresponded with ground displacement rates of up to ~−1.4 cm/yr, but not all the coastline segments with high annual mean erosion rates were associated with local mean subsidence. The causes of ground displacements and coastline erosion were analyzed, and results were interpreted by integrating spatial ancillary information. Results indicate that rapid urbanization, construction on reclaimed land, coastline erosion favoring seawater intrusion, failed drainage/sewerage networks, and soil liquefaction are contributing to the site-specific variations in the land displacement in Karachi.
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3TA13894A
Publisher: Wiley
Date: 04-03-2014
Abstract: Ultrathin graphitic carbon nitride (g-C3N4) nanosheets, due to their interesting two-dimensional graphene-like structure and unique physicochemical properties, have attracted great research attention recently. Here, a new approach is developed to prepare, for the first time, proton-functionalized ultrathin g-C3N4 nanosheets by sonication-exfoliation of bulk g-C3N4 under an acid condition. This method not only reduces the exfoliation time from more than 10 h to 2 h, but also endows the nanosheets with positive charges. Besides retaining the properties of g-C3N4, the obtained nanosheets with the thickness of 2-4 nm (i.e., 6-12 atomic monolayers) also exhibit large specific surface area of 305 m(2) g(-1), enhanced fluorescence intensity, and excellent water dispersion stability due to their surface protonation and ultrathin morphology. The well-dispersed protonated g-C3N4 nanosheets are able to interact with negatively charged heparin, which results in the quenching of g-C3N4 fluorescence. A highly sensitive and highly selective heparin sensing platform based on protonated g-C3N4 nanosheets is established. This metal-free and fluorophore label-free system can reach the lowest heparin detection limit of 18 ng mL(-1).
Publisher: Elsevier BV
Date: 02-2021
Publisher: American Chemical Society (ACS)
Date: 20-02-2015
DOI: 10.1021/LA5044415
Abstract: Green and simple synthesis of high-quality colloidal quantum dots (CQDs) is of great importance and highly anticipated yet not fully implemented. Herein, we achieve the direct conversion of natural minerals to highly uniform, crystalline lead sulfide CQDs based on laser irradiation in liquid. The trivial fragmentation of mineral particles by an intense nanosecond laser was found to create a localized high degree of monomer supersaturation in oleic acid, initiating the LaMer growth of uniform CQDs. The photoconductive device made of these CQDs exhibits a competitive temporal response of photocurrent with those highly sensitive photodetectors based on PbS CQDs reported in the literature. Our synthesis strategy paves the way for the most environmentally friendly and convenient mass production of high-quality uniform CQDs.
Publisher: American Chemical Society (ACS)
Date: 08-10-2019
Publisher: American Chemical Society (ACS)
Date: 12-11-1999
DOI: 10.1021/LA990785Q
Publisher: Wiley
Date: 16-03-2023
Abstract: Zn electrodes in aqueous media exhibit an unstable Zn/electrolyte interface due to severe parasitic reactions and dendrite formation. Here, a dynamic Zn interface modulation based on the molecular switch strategy is reported by hiring γ‐butyrolactone (GBL) in ZnCl 2 /H 2 O electrolyte. During Zn plating, the increased interfacial alkalinity triggers molecular switch from GBL to γ‐hydroxybutyrate (GHB). GHB strongly anchors on Zn surface via triple Zn−O bonding, leading to suppressive hydrogen evolution and texture‐regulated Zn morphology. Upon Zn stripping, the fluctuant pH turns the molecular switch reaction off through the cyclization of GHB to GBL. This dynamic molecular switch strategy enables high Zn reversibility with Coulombic efficiency of 99.8 % and Zn||iodine batteries with high‐cyclability under high Zn depth of discharge (50 %). This study demonstrates the importance of dynamic modulation for Zn electrode and realizes the reversible molecular switch strategy to enhance its reversibility.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR05299H
Abstract: The design and synthesis of metal oxide nanomaterials is one of the key steps for achieving highly efficient energy conversion and storage on an industrial scale.
Publisher: Wiley
Date: 04-02-2019
Abstract: Lithium-oxygen (Li-O
Publisher: Wiley
Date: 15-11-2022
Abstract: Photocatalytic performance can be optimized via introduction of reactive sites. However, it is practically difficult to engineer these on specific photocatalyst surfaces, because of limited understanding of atomic‐level structure‐activity. Here we report a facile sonication‐assisted chemical reduction for specific facets regulation via oxygen deprivation on Bi‐based photocatalysts. The modified Bi 2 MoO 6 nanosheets exhibit 61.5 and 12.4 μmol g −1 for CO and CH 4 production respectively, ≈3 times greater than for pristine catalyst, together with excellent stability/reproducibility of ≈20 h. By combining advanced characterizations and simulation, we confirm the reaction mechanism on surface‐regulated photocatalysts, namely, induced defects on highly‐active surface accelerate charge separation/transfer and lower the energy barrier for surface CO 2 adsorption/activation/reduction. Promisingly, this method appears generalizable to a wider range of materials.
Publisher: American Chemical Society (ACS)
Date: 29-09-2004
DOI: 10.1021/JP047479S
Publisher: American Chemical Society (ACS)
Date: 23-07-1999
DOI: 10.1021/LA981460X
Publisher: Wiley
Date: 21-05-2013
Publisher: Research Square Platform LLC
Date: 10-09-2020
DOI: 10.21203/RS.3.RS-67358/V1
Abstract: Urea oxidation, a key process in energy and environmental science, faces challenges because of the insufficient understanding of its mechanism and the lack of efficient catalysts. Here we demonstrate that nickel ferrocyanide (Ni 2 Fe(CN) 6 ) molecular catalyst supported on Ni form can drive urea oxidation reaction (UOR) with the record electrochemical activity and stability among all supported catalysts reported so far. A combination of kinetics data, in-situ spectroscopic measurements and energy computations suggests a new UOR pathway that delivers such outstanding performance. Different from most studied Ni-based catalysts with NiOOH derivative as a real catalytically active site for UOR, Ni 2 Fe(CN) 6 appears to be a next-generation catalyst able to directly facilitate a two-step reaction pathway involving a critical reaction of intermediate ammonia’s production (on Ni site) and oxidation (on Fe site). Due to the alternative rate-determining step with a more favorable thermal energetics, Ni 2 Fe(CN) 6 broke the limiting activity of the reported so far UOR catalysts. As a result, the UOR process on Ni 2 Fe(CN) 6 can replace conventional water oxidation process in various energy-saving systems for hydrogen and hydrogen peroxide production.
Publisher: Wiley
Date: 24-02-2021
Publisher: Wiley
Date: 18-04-2019
Abstract: Heteroatom‐doped carbon materials with expanded interlayer distance have been widely studied as anodes for sodium‐ion batteries (SIBs). However, it remains unexplored to further enlarge the interlayer spacing and reveal the influence of heteroatom doping on carbon nanostructures for developing more efficient SIB anode materials. Here, a series of N‐rich few‐layer graphene (N‐FLG) with tuneable interlayer distance ranging from 0.45 to 0.51 nm is successfully synthesized by annealing graphitic carbon nitride (g‐C 3 N 4 ) under zinc catalysis and selected temperature ( T = 700, 800, and 900 °C). More significantly, the correlation between N dopants and interlayer distance of resultant N‐FLG‐T highlights the effect of pyrrolic N on the enlargement of graphene interlayer spacing, due to its stronger electrostatic repulsion. As a consequence, N‐FLG‐800 achieves the optimal properties in terms of interlayer spacing, nitrogen configuration and electronic conductivity. When used as an anode for SIBs, N‐FLG‐800 shows remarkable Na + storage performance with ultrahigh rate capability (56.6 mAh g −1 at 40 A g −1 ) and excellent long‐term stability (211.3 mAh g −1 at 0.5 A g −1 after 2000 cycles), demonstrating the effectiveness of material design.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2022
DOI: 10.1038/S41467-022-31427-9
Abstract: Electroreduction of carbon dioxide (CO 2 ) into multicarbon products provides possibility of large-scale chemicals production and is therefore of significant research and commercial interest. However, the production efficiency for ethanol (EtOH), a significant chemical feedstock, is impractically low because of limited selectivity, especially under high current operation. Here we report a new silver–modified copper–oxide catalyst (dCu 2 O/Ag 2.3% ) that exhibits a significant Faradaic efficiency of 40.8% and energy efficiency of 22.3% for boosted EtOH production. Importantly, it achieves CO 2 –to–ethanol conversion under high current operation with partial current density of 326.4 mA cm −2 at −0.87 V vs reversible hydrogen electrode to rank highly significantly amongst reported Cu–based catalysts. Based on in situ spectra studies we show that significantly boosted production results from tailored introduction of Ag to optimize the coordinated number and oxide state of surface Cu sites, in which the * CO adsorption is steered as both atop and bridge configuration to trigger asymmetric C–C coupling for stablization of EtOH intermediates.
Publisher: Wiley
Date: 17-08-2023
Abstract: As a burgeoning electrolyte system, eutectic electrolytes based on ZnCl 2 /Zn(CF 3 SO 3 ) 2 /Zn(TFSI) 2 have been widely proposed in advanced Zn‐I 2 batteries however, safety and cost concerns significantly limit their applications. Here, we report new‐type ZnSO 4 ‐based eutectic electrolytes that are both safe and cost‐effective. Their universality is evident in various solvents of polyhydric alcohols, in which multiple −OH groups not only involve in Zn 2+ solvation but also interact with water, resulting in the high stability of electrolytes. Taking propylene glycol‐based hydrated eutectic electrolyte as an ex le, it features significant advantages in non‐flammability and low price that is /200 cost of Zn(CF 3 SO 3 ) 2 /Zn(TFSI) 2 ‐based eutectic electrolytes. Moreover, its effectiveness in confining the shuttle effects of I 2 cathode and side reactions of Zn anodes is evidenced, resulting in Zn‐I 2 cells with high reversibility at 1 C and 91.4 % capacity remaining under 20 C. After scaling up to the pouch cell with a record mass loading of 33.3 mg cm −2 , super‐high‐capacity retention of 96.7 % is achieved after 500 cycles, which exceeds other aqueous counterparts. This work significantly broadens the eutectic electrolyte family for advanced Zn battery design.
Publisher: Wiley
Date: 21-09-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0TA04244G
Abstract: The compressive stress at the NiOOH/NiO interface, created through the battery conversion chemistry, is found to influence the OER performance.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6EE01297C
Abstract: A nitrogen-doped Co 3 (PO 4 ) 2 @nanocarbon hybrid was developed as an oxygen reduction reaction (ORR) catalyst and exhibits outstanding catalytic performance with high activity, long-term stability and a four-electron transfer pathway.
Publisher: Wiley
Date: 13-11-2020
Publisher: Wiley
Date: 28-03-2013
Abstract: Graphene-based hydrogels can be used as supercapacitor electrodes because of their excellent conductivity, their large surface area and their high compatibility with electrolytes. Nevertheless, the large aspect ratio of graphene sheets limits the kinetics of processes occurring in the electrode of supercapacitors. In this study, we have introduced in-plane and out-of-plane pores into a graphene-nickel hydroxide (Ni(OH)2) hybrid hydrogel, which facilitates charge and ion transport in the electrode. Due to its optimised chemistry and architecture, the hybrid electrode demonstrates excellent electrochemical properties with a combination of high charge storage capacitance, fast rate capability and stable cycling performance. Remarkably, the Ni(OH)2 in the hybrid contributes a capacitance as high as 3138.5 F g(-1), which is comparable to its theoretical capacitance, suggesting that such structure facilitates effectively charge-transfer reactions in electrodes. This work provides a facile pathway for tailoring the porosity of graphene-based materials for improved performances. Moreover, this work has also furthered our understanding in the effect of pore and hydrogel structures on the electrochemical properties of materials.
Publisher: Springer Science and Business Media LLC
Date: 15-11-2017
DOI: 10.1038/S41467-017-01872-Y
Abstract: Designing high-performance and cost-effective electrocatalysts toward oxygen evolution and hydrogen evolution reactions in water–alkali electrolyzers is pivotal for large-scale and sustainable hydrogen production. Earth-abundant transition metal oxide-based catalysts are particularly active for oxygen evolution reaction however, they are generally considered inactive toward hydrogen evolution reaction. Here, we show that strain engineering of the outermost surface of cobalt(II) oxide nanorods can turn them into efficient electrocatalysts for the hydrogen evolution reaction. They are competitive with the best electrocatalysts for this reaction in alkaline media so far. Our theoretical and experimental results demonstrate that the tensile strain strongly couples the atomic, electronic structure properties and the activity of the cobalt(II) oxide surface, which results in the creation of a large quantity of oxygen vacancies that facilitate water dissociation, and fine tunes the electronic structure to weaken hydrogen adsorption toward the optimum region.
Publisher: American Chemical Society (ACS)
Date: 13-05-2021
DOI: 10.1021/JACS.1C03135
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM33992G
Publisher: Wiley
Date: 24-02-2021
Publisher: Wiley
Date: 15-11-2016
Abstract: Design and synthesis of porous and hollow carbon spheres have attracted considerable interest in the past decade due to their superior physicochemical properties and widespread applications. However, it is still a big challenge to achieve controllable synthesis of hollow carbon nanospheres with center-radial large mesopores in the shells and inner surface roughness. Herein, porous hollow carbon nanospheres (PHCNs) are successfully synthesized with tunable center-radial mesopore channels in the shells and crater-like inner surfaces by employing dendrimer-like mesoporous silica nanospheres (DMSNs) as hard templates. Compared with conventional mesoporous nanospheres, DMSN templates not only result in the formation of center-radial large mesopores in the shells, but also produce a crater-like inner surface. PHCNs can be tuned from open center-radial mesoporous shells to relatively closed microporous shells. After functionalization with polyethyleneimine (PEI) and poly(ethylene glycol) (PEG), PHCNs not only have negligible cytotoxicity, excellent photothermal property, and high coloading capacity of 482 µg of doxorubicin and 44 µg of siRNA per mg, but can also efficiently deliver these substances into cells, thus displaying enhanced cancer cell killing capacity by triple-combination therapy.
Publisher: Wiley
Date: 14-08-2017
Publisher: Wiley
Date: 15-03-2018
Abstract: Conventional development of nanomaterials for efficient electrocatalysis is largely based on performance-oriented trial-and-error/iterative approaches, while a rational design approach at the atomic/molecular level is yet to be found. Here, inspired by a fundamental understanding of the mechanism for both oxygen and hydrogen evolution half reactions (OER/HER), a unique strategy is presented to engineer RuO
Publisher: Wiley
Date: 03-10-2022
Abstract: The poor Zn reversibility has been criticized for limiting applications of aqueous Zn‐ion batteries (ZIBs) however, its behavior in aqueous media is not fully uncovered yet. Here, this knowledge gap is addressed, indicating that Zn electrodes face a O 2 ‐involving corrosion, besides H 2 evolution and dendrite growth. Differing from aqueous Li/Na batteries, removing O 2 cannot enhance ZIB performance because of the aggravated competing H 2 evolution. To address Zn issues, a one‐off electrolyte strategy is reported by introducing the triple‐function C 3 H 7 Na 2 O 6 P, which can take effects during the shelf time of battery. It regulates H + concentration and reduces free‐water activity, inhibiting H 2 evolution. A self‐healing solid/electrolyte interphase (SEI) can be triggered before battery operation, which suppresses O 2 adsorption corrosion and dendritic deposition. Consequently, a high Zn reversibility of 99.6% is achieved under a high discharge depth of 85%. The pouch full‐cell with a lean electrolyte displays a record lifespan with capacity retention of 95.5% after 500 cycles. This study not only looks deeply into Zn behavior in aqueous media but also underscores rules for the design of active metal anodes, including Zn and Li metals, during shelf time toward real applications.
Publisher: Wiley
Date: 14-05-2201
Publisher: Wiley
Date: 07-10-2014
Abstract: The application of various earth-abundant Ni species, such as NiS, Ni, Ni(OH)2 , and NiO, as a co-catalyst in a Znx Cd1-x S system for visible-light photocatalytic H2 production was investigated for the first time. The loading of Ni or NiS enhanced the photocatalytic activity of Znx Cd1-x S because they could promote the electron transfer at the interface with Znx Cd1-x S and catalyze the H2 evolution. Surprisingly, Ni(OH)2 -loaded Znx Cd1-x S exhibits a very high photocatalytic H2 -production rate of 7160 μmol h(-1) g(-1) with a quantum efficiency of 29.5 % at 420 nm, which represents one of the most efficient metal sulfide photocatalysts without a Pt co-catalyst to date. This outstanding activity arises from the pronounced synergetic effect between Ni(OH)2 and metallic Ni formed in situ during the photocatalytic reaction. However, the loading of NiO deactivated the activity of Znx Cd1-x S because of their unmatched conduction band positions. This paper reports the optimization of the Znx Cd1-x S system by selecting an appropriate Ni-based co-catalyst, Ni(OH)2 , from a series of Ni species to achieve the highest photocatalytic H2 -production activity for the first time and also reveals the roles of these Ni species in the photocatalytic activity.
Publisher: American Chemical Society (ACS)
Date: 08-02-2010
DOI: 10.1021/JA906274T
Abstract: Low-temperature catalysts of mesoporous Co(3)O(4) and Au/Co(3)O(4) with high catalytic activities for the trace ethylene oxidation at 0 degrees C are reported in this paper. The catalysts were prepared by using the nanocasting method, and the mesostructure was replicated from three-dimensional (3D) cubic KIT-6 silicas. High resolution transmission electron microscopy (HRTEM) studies revealed that {110} facets were the exposed active surfaces in the mesoporous Co(3)O(4), whereas the Co(3)O(4) nanosheets prepared by the precipitation method exhibited the most exposed {112} facets. We found that the mesoporous Co(3)O(4) was significantly more active for ethylene oxidation than the Co(3)O(4) nanosheets. The results indicated that the crystal facet {110} of Co(3)O(4) played an essential role in determining its catalytic oxidation performance. The synthesized Au/Co(3)O(4) materials, in which the gold nanoparticles were assembled into the pore walls of the Co(3)O(4) mesoporous support, exhibited stable, highly dispersed, and exposed gold sites. Gold nanoparticles present on Co(3)O(4) readily produced surface-active oxygen species and promoted ethylene oxidation to achieve a 76% conversion at 0 degrees C, which is the highest conversion reported yet.
Publisher: Wiley
Date: 19-01-2011
Abstract: Magnetic nanocomposites with well-defined mesoporous structures, shapes, and tailored properties are of immense scientific and technological interest. This review article is devoted to the progress in the synthesis and applications of magnetic mesoporous materials. The first part briefly reviews various general methods developed for producing magnetic nanoparticles (NPs). The second presents and categorizes the synthesis of magnetic nanocomposites with mesoporous structures. These nanocomposites are broadly categorized into four types: monodisperse magnetic nanocrystals embedded in mesoporous nanospheres, microspheres encapsulating magnetic cores into perpendicularly aligned mesoporous shells, ordered mesoporous materials loaded with magnetic NPs inside the porous channels or cages, and rattle-type magnetic nanocomposites. The third section reviews the potential applications of the magnetic nanocomposites with mesoporous structures in the areas of heath care, catalysis, and environmental separation. The final section offers a summary and future perspectives on the state-of-the art in this area.
Publisher: American Chemical Society (ACS)
Date: 13-06-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1NR10224A
Abstract: Mesoporous silica nanoparticles (MSNs) provide a non-invasive and biocompatible delivery platform for a broad range of applications in therapeutics, pharmaceuticals and diagnosis. The creation of smart, stimuli-responsive systems that respond to subtle changes in the local cellular environment are likely to yield long term solutions to many of the current drug/gene/DNA/RNA delivery problems. In addition, MSNs have proven to be promising supports for enzyme immobilisation, enabling the enzymes to retain their activity, affording them greater potential for wide applications in biocatalysis and energy. This review provides a comprehensive summary of the advances made in the last decade and a future outlook on possible applications of MSNs as nanocontainers for storage and delivery of biomolecules. We discuss some of the important factors affecting the adsorption and release of biomolecules in MSNs and review of the cytotoxicity aspects of such nanomaterials. The review also highlights some promising work on enzyme immobilisation using mesoporous silica nanoparticles.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5NH00002E
Abstract: Nitrogen doped graphene hydrogel electrocatalysts with in situ deposited cobalt phosphate demonstrated excellent catalytic performance toward oxygen evolution in a neutral electrolyte.
Publisher: Springer Science and Business Media LLC
Date: 05-2008
DOI: 10.1038/NATURE06964
Abstract: Owing to their scientific and technological importance, inorganic single crystals with highly reactive surfaces have long been studied. Unfortunately, surfaces with high reactivity usually diminish rapidly during the crystal growth process as a result of the minimization of surface energy. A typical ex le is titanium dioxide (TiO2), which has promising energy and environmental applications. Most available anatase TiO(2) crystals are dominated by the thermodynamically stable {101} facets (more than 94 per cent, according to the Wulff construction), rather than the much more reactive {001} facets. Here we demonstrate that for fluorine-terminated surfaces this relative stability is reversed: {001} is energetically preferable to {101}. We explored this effect systematically for a range of non-metallic adsorbate atoms by first-principle quantum chemical calculations. On the basis of theoretical predictions, we have synthesized uniform anatase TiO(2) single crystals with a high percentage (47 per cent) of {001} facets using hydrofluoric acid as a morphology controlling agent. Moreover, the fluorated surface of anatase single crystals can easily be cleaned using heat treatment to render a fluorine-free surface without altering the crystal structure and morphology.
Publisher: Springer Science and Business Media LLC
Date: 06-08-2022
DOI: 10.1038/S41467-022-32256-6
Abstract: High-performance and low-cost photocatalysts play the key role in achieving the large-scale solar hydrogen production. In this work, we report a liquid-exfoliation approach to prepare NiPS 3 ultrathin nanosheets as a versatile platform to greatly improve the light-induced hydrogen production on various photocatalysts, including TiO 2 , CdS, In 2 ZnS 4 and C 3 N 4 . The superb visible-light-induced hydrogen production rate (13,600 μmol h −1 g −1 ) is achieved on NiPS 3 /CdS hetero-junction with the highest improvement factor (~1,667%) compared with that of pure CdS. This significantly better performance is attributed to the strongly correlated NiPS 3 /CdS interface assuring efficient electron-hole dissociation/transport, as well as abundant atomic-level edge P/S sites and activated basal S sites on NiPS 3 ultrathin nanosheets advancing hydrogen evolution. These findings are revealed by the state-of-art characterizations and theoretical computations. Our work for the first time demonstrates the great potential of metal phosphorous chalcogenide as a general platform to tremendously raise the performance of different photocatalysts.
Publisher: Wiley
Date: 08-02-2018
Abstract: Research into efficient synthesis, fundamental properties, and potential applications of phosphorene is currently the subject of intense investigation. Herein, solution-processed phosphorene or few-layer black phosphorus (FL-BP) sheets are prepared using a microwave exfoliation method and used in photoelectrochemical cells. Based on experimental and theoretical (DFT) studies, the FL-BP sheets are found to act as catalytically active sites and show excellent electrocatalytic activity for triiodide reduction in dye-sensitized solar cells. Importantly, the device fabricated based on the newly designed cobalt sulfide (CoS
Publisher: Wiley
Date: 02-08-2021
Abstract: The shuttling of soluble lithium polysulfides between the electrodes leads to serious capacity fading and excess use of electrolyte, which severely bottlenecks practical use of Li‐S batteries. Here, selective catalysis is proposed as a fundamental remedy for the consecutive solid‐liquid‐solid sulfur redox reactions. The proof‐of‐concept Indium (In)‐based catalyst targetedly decelerates the solid‐liquid conversion, dissolution of elemental sulfur to polysulfides, while accelerates the liquid‐solid conversion, deposition of polysulfides into insoluble Li 2 S, which basically reduces accumulation of polysulfides in electrolyte, finally inhibiting the shuttle effect. The selective catalysis is revealed, experimentally and theoretically, by changes of activation energies and kinetic currents, modified reaction pathway together with the probed dynamically changing catalyst (LiInS 2 catalyst), and gradual deactivation of the In‐based catalyst. The In‐based battery works steadily over 1000 cycles at 4.0 C and yields an initial areal capacity up to 9.4 mAh cm −2 with a sulfur loading of ≈9.0 mg cm −2 .
Publisher: American Chemical Society (ACS)
Date: 13-03-2023
DOI: 10.1021/JACS.2C13590
Publisher: Springer Science and Business Media LLC
Date: 12-09-2016
Publisher: SAGE Publications
Date: 11-05-2014
Abstract: A small amount of commercial functional nanosilica was mechanically mixed with epoxy to enhance the composite fracture toughness. Nanosilicas with amino and epoxide functional groups show strong interfaces with epoxy, which suppress large aggregations and enhance resin-wettability, hence enhancing the fracture toughness of epoxy composites. Compared with other reports, less nanosilica content was needed to achieve the same fracture toughness values or similar enhancement ratio. Due to their commercial availability, the low-cost of the raw material and simple fabrication method, those nanocomposites have the potential for large-scale applications.
Publisher: Wiley
Date: 14-09-2018
Publisher: American Chemical Society (ACS)
Date: 04-08-2022
DOI: 10.1021/JACS.2C06820
Abstract: An ere-level current density of CO
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.JHAZMAT.2011.02.078
Abstract: Triphosphate (TPP) is an important form of phosphate pollutants while its removal investigation has been just started now. This research examined the removal of triphosphate using Mg(2-x)Ca(x)FeCl-LDH (x = 0-2) as absorbents. We found that the removal of triphosphate over Mg(2)FeCl-LDH mainly underwent the surface adsorption and the near-edge intercalation, with the practical removal amount (9-11 mg(P)/g) corresponding to 10-15% of the theoretical one. In contrast, Ca(2)FeCl-LDH removed a higher amount of triphosphate (56.4 mg(P)/g). The comprehensive analysis of the triphosphate-uptake products with XRD/XPS/FTIR reveals that Ca(2)FeCl-LDH dissolves first and then released Ca(2+) ions react with triphosphate (TPP) to form insoluble Ca-TPP precipitate. Combination of these two different removal mechanisms enables Mg(0.5)Ca(1.5)FeCl-LDH to take up 84.2mg(P)/g from aqueous solution under similar conditions.
Publisher: American Chemical Society (ACS)
Date: 06-02-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0CC04779A
Abstract: High CO selectivity for the CO 2 electroreduction reaction was achieved on Ni–Cu bimetallic catalysts. We observed that changing the Cu content in the catalysts causes charge redistribution which results in a negative correlation with CO selectivity.
Publisher: Wiley
Date: 02-05-2019
Publisher: American Chemical Society (ACS)
Date: 05-2014
DOI: 10.1021/NN501434A
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0JM03132A
Publisher: Elsevier BV
Date: 07-2006
Publisher: American Chemical Society (ACS)
Date: 30-06-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM00068C
Publisher: Elsevier
Date: 2000
Publisher: Wiley
Date: 16-10-2021
Publisher: Wiley
Date: 15-11-2022
Abstract: Photocatalytic performance can be optimized via introduction of reactive sites. However, it is practically difficult to engineer these on specific photocatalyst surfaces, because of limited understanding of atomic‐level structure‐activity. Here we report a facile sonication‐assisted chemical reduction for specific facets regulation via oxygen deprivation on Bi‐based photocatalysts. The modified Bi 2 MoO 6 nanosheets exhibit 61.5 and 12.4 μmol g −1 for CO and CH 4 production respectively, ≈3 times greater than for pristine catalyst, together with excellent stability/reproducibility of ≈20 h. By combining advanced characterizations and simulation, we confirm the reaction mechanism on surface‐regulated photocatalysts, namely, induced defects on highly‐active surface accelerate charge separation/transfer and lower the energy barrier for surface CO 2 adsorption/activation/reduction. Promisingly, this method appears generalizable to a wider range of materials.
Publisher: Elsevier BV
Date: 15-04-2010
DOI: 10.1016/J.JHAZMAT.2009.11.012
Abstract: This research has demonstrated that the Friedel phase, e.g. a chloride-containing hydrocalumite (Ca(2)Al(OH)(6)Cl(H(2)O)(2) x mH(2)O), can rapidly adsorb large amounts of SeO(4)(2-) (up to 1.37 mmol/g). SeO(4)(2-) is removed via anionic exchange, as evidenced by the expansion of the d-spacing from 0.78 nm of Cl-hydrocalumite to 0.97-0.98 nm of SeO(4)-hydrocalumite. The newly formed SeO(4)-adsorbed hydrocalumite is stable in water at pH 4-13, indicating the strong fixation of selenate within the phase. In contrast, intercalated selenate in the Freidel phase can be recovered by desorbing in the NaCl solution, which can also regenerate and recycle the used adsorbent. The findings in this research strongly suggest that the Friedel phase is a new, environmentally friendly and cost-effective adsorbent to adsorb selenate from wastewater streams and dilute solutions.
Publisher: Elsevier BV
Date: 05-2008
Publisher: American Chemical Society (ACS)
Date: 15-09-2016
Abstract: As substitutes for precious cathodic Pt/C and anodic IrO2 in electrolytic water splitting cells, a bifunctional catalyst electrode (Fe- and O-doped Co2P grown on nickel foam) has been fabricated by manipulating the cations and anions of metal compounds. The modified catalyst electrode exhibits both superior HER and OER performances with high activity, favorable kinetics, and outstanding durability. The overall ability toward water splitting is especially extraordinary, requiring a small overpotential of 333.5 mV to gain a 10 mA cm(-2) current density. A study on the electrocatalytic mechanism reveals that the atomic modulation between cation and anion plays an important role in optimizing the electrocatalytic activity, which greatly expands the active sites in the electrocatalyst. Further, the three-dimensional conductive porous network is highly advantageous for the exposure of active species, the transport of bubble products, and the transfer of electrons and charges, which substantially boosts reaction kinetics and structure stability.
Publisher: Elsevier BV
Date: 05-2020
Publisher: Wiley
Date: 30-09-2019
Publisher: Wiley
Date: 17-04-2020
Publisher: Wiley
Date: 13-03-2018
Abstract: Nanophase-separated membranes hold promise for fast molecule or ion transfer. However, development and practical application are significantly hindered by both the difficulty of chemical modification and nanophase instability. This can be addressed by organic-inorganic hybridization of functional fillers with a precise distribution in specific nanophase. Here, a molecular-level hybridization for nanophase-separated Nafion using 2-5 nm quantum dots (QDs) as a new smart filler is demonstrated. Two kinds of QDs are prepared and used: hydrophilic polymer-like QDs (PQDs) and hydrophobic graphene oxide QDs (GQDs). Because of selective interactions, QDs offer advantages of matched structural size and automatic recognition with the nanophase. A distinctive synthesis of subordinate-assembly, in which QDs are driven by the self-assembly of Nafion affinity chains, is reported. This results in a precise distribution of QDs in the ionic, or backbone, nanophases of Nafion. The resulting PQDs in the ionic nanophase significantly increase membrane proton conduction and device output-power without loss of mechanical stability. This is difficult to realize with conventional fillers. The GQDs in the backbone nanophase reduce the crystallinity and significantly augment membrane water uptake and swelling capacities.
Publisher: American Chemical Society (ACS)
Date: 03-01-2020
DOI: 10.1021/JACS.9B11774
Abstract: Lean-electrolyte conditions are highly pursued for practical lithium (Li) metal batteries. The previous studies on the Li metal anodes, in general, exhibited good stability with a large excess of electrolyte. However, the targeted design of Li hosts under relatively low electrolyte conditions has been rarely studied so far. Herein, we have shown that electrolyte consumption severely affects the cycling stability of Li metal anode. Considering carbon hosts as typical ex les, we innovatively employed in situ synchrotron X-ray diffraction, in situ Raman spectroscopy, and theoretical computations to obtain a better understanding of the Li nucleation/deposition processes. We also showed the usefulness of in situ electrochemical impedance spectra to analyze interfacial fluctuation at the Li/electrolyte interface, together with nuclear magnetic resonance data to quantify electrolyte consumption. We have found that uneven Li nucleation/deposition and the crack of surface-area-derived solid-electrolyte interface (SEI) layer both lead to a great consumption of electrolyte. Then, we suggested a design principle for Li host to overcome the electrolyte loss, that is, uneven growth of the Li structure and the crack of the SEI layer must be simultaneously controlled. As a proof of concept, we demonstrated the usefulness of a 3D low-surface-area defective graphene host (L-DG) to control Li nucleation/deposition and stabilize the SEI layer, contributing to a highly reversible Li plating/stripping. As a result, such a Li host can achieve stable cycles (e.g., 1.0 mAh cm
Publisher: Wiley
Date: 27-09-2020
Publisher: Elsevier BV
Date: 09-2009
Publisher: Elsevier BV
Date: 04-2006
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3TB21015D
Publisher: Wiley
Date: 10-03-2021
Abstract: Compared to modern fossil‐fuel‐based refineries, the emerging electrocatalytic refinery (e‐refinery) is a more sustainable and environmentally benign strategy to convert renewable feedstocks and energy sources into transportable fuels and value‐added chemicals. A crucial step in conducting e‐refinery processes is the development of appropriate reactions and optimal electrocatalysts for efficient cleavage and formation of chemical bonds. However, compared to well‐studied primary reactions (e.g., O 2 reduction, water splitting), the mechanistic aspects and materials design for emerging complex reactions are yet to be settled. To address this challenge, herein, we first present fundamentals of heterogeneous electrocatalysis and some primary reactions, and then implement these to establish the framework of e‐refinery by coupling in situ generated intermediates (integrated reactions) or products (tandem reactions). We also present a set of materials design principles and strategies to efficiently manipulate the reaction intermediates and pathways.
Publisher: Wiley
Date: 12-02-2023
Abstract: Poor electronic and ionic conductivity of electrode materials at low temperatures of −20 °C and below has significantly impeded development of batteries for cold conditions. However, for the first time, layer‐structured metallic vanadium diselenide (1T‐VSe 2 ) is reported as a cathode material for low‐temperature Mg 2+ /Li + hybrid batteries. A high electronic conductivity and fast ion diffusion kinetics for 1T‐VSe 2 are demonstrated at selected temperatures, and a very safe 1T‐VSe 2 /Mg battery for operation at temperatures to −40 °C. The battery exhibits 97% capacity retention over 500 cycles, which is better performance than reported Mg‐based batteries. The Jahn–Teller effect in compressed configuration is initiated in 1T‐VSe 2 with the change of electronic state occurring on electrochemical intercalation of alkali metal ions. Using combined experiment and theory via operando synchrotron X‐ray diffraction, ex situ X‐ray absorption spectroscopy and DFT computation, it is confirmed that the weak Jahn–Teller distortion contributes significantly to fast‐overall kinetics, structural stability, and high electronic conductivity of the electrode. Understanding at an atomic level of the mechanism is demonstrated, that provides valuable guidance in designing high‐performance electrode materials for low‐temperature batteries.
Publisher: Springer Science and Business Media LLC
Date: 28-04-2014
DOI: 10.1038/NCOMMS4783
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC13467A
Abstract: Co(2+)-doped CdSe colloidal nanowires with tunable size and dopant concentration have been prepared by a solution-liquid-solid (SLS) approach for the first time. These doped nanowires exhibit anomalous photoluminescence temperature dependence in comparison with undoped nanowires.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5EE03732H
Abstract: In this review, we focus on analysing the fundamental electronic, optical and chemical properties of 2D phosphorene to assess its suitability as a metal-free water splitting photocatalyst.
Publisher: Wiley
Date: 26-03-2020
Publisher: American Chemical Society (ACS)
Date: 26-02-2019
Publisher: American Chemical Society (ACS)
Date: 07-10-2013
DOI: 10.1021/NN404444R
Abstract: In this work, we report a three-dimensional (3D) oxygen evolution reaction (OER) catalyst with hierarchical pores for water splitting. The remarkable features of well-developed in- and out-of-plane pores, 3D conductive networks, and N-doping have greatly promoted the transport in electrodes and assured high catalytic efficiency. The 3D hybrid paper of N-doped graphene-NiCo2O4 has shown a remarkable OER catalytic activity that was comparable to that of previously reported noble metal catalysts (IrO2). The catalytic process occurred with favorable kinetics and strong durability. The dual-active-site mechanism is responsible for the excellent performance of the hybrid catalyst that is, the edges of NiCo2O4 and the N (O)-metal (Ni or Co) bonds are both active sites. This study affords a new strategy to achieve optimal performance in 3D catalysts, which may be extended to the preparation of other 3D hybrid materials for a broad range of technological applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/C0CC02973D
Abstract: TiO(2) and SnO(2)@TiO(2) hollow spheres assembled from anatase TiO(2) nanosheets with exposed (001) high-energy facets are constructed via a templating approach, and the as-prepared s les exhibit enhanced lithium storage properties.
Publisher: Wiley
Date: 30-11-2016
Publisher: IOP Publishing
Date: 09-01-2014
DOI: 10.1088/0957-4484/25/5/055701
Abstract: The development of functional nanocarriers that can enhance the cellular delivery of a variety of nucleic acid agents is important in many biomedical applications such as siRNA therapy. We report the synthesis of large pore mesoporous silica nanoparticles (LPMSN) loaded with iron oxide and covalently modified by polyethyleneimine (denoted PEI-Fe-LPMSN) as carriers for gene delivery. The LPMSN have a particle size of ∼200 nm and a large pore size of 11 nm. The large pore size is essential for the formation of large iron oxide nanoparticles to increase the magnetic properties and the adsorption capacity of siRNA molecules. The magnetic property facilitates the cellular uptake of nanocarriers under an external magnetic field. PEI is covalently grafted on the silica surface to enhance the nanocarriers' affinity against siRNA molecules and to improve gene silencing performance. The PEI-Fe-LPMSN delivered siRNA-PLK1 effectively into osteosarcoma cancer cells, leading to cell viability inhibition of 80%, higher compared to the 50% reduction when the same dose of siRNA was delivered by a commercial product, oligofectamine.
Publisher: Springer Science and Business Media LLC
Date: 29-09-2021
DOI: 10.1038/S41467-021-26056-7
Abstract: Sulfur is an important electrode material in metal−sulfur batteries. It is usually coupled with metal anodes and undergoes electrochemical reduction to form metal sulfides. Herein, we demonstrate, for the first time, the reversible sulfur oxidation process in AlCl 3 /carbamide ionic liquid, where sulfur is electrochemically oxidized by AlCl 4 − to form AlSCl 7 . The sulfur oxidation is: 1) highly reversible with an efficiency of ~94% and 2) workable within a wide range of high potentials. As a result, the Al−S battery based on sulfur oxidation can be cycled steadily around ~1.8 V, which is the highest operation voltage in Al−S batteries. The study of sulfur oxidation process benefits the understanding of sulfur chemistry and provides a valuable inspiration for the design of other high-voltage metal−sulfur batteries, not limited to Al−S configurations.
Publisher: American Chemical Society (ACS)
Date: 05-09-2019
Publisher: Wiley
Date: 27-12-2016
Abstract: Atomically and electronically coupled Pt and CoO hybrid nanocatalysts are fabricated for electrocatalytic oxygen reduction reaction. The atomic coupling between the Pt and the CoO endows precise control of the atomic interface between the Pt and the CoO, which directly results in electron donation from the CoO to the Pt, and thus favorable tuning of the electronic structure of the Pt.
Publisher: Wiley
Date: 21-08-2013
Abstract: Semiconductor materials with an inverse opal structure have previously demonstrated promise for photovoltaic applications. However, their use in solar cells is still restricted by their poor electron transfer properties. Here, highly conductive CdS inverse opal structures are prepared via a multistep process, where CdS inverse opal backbones are first built up on conductive glass substrates via co‐deposition of CdS quantum dots and polystyrene microspheres, followed by calcination, after which subsequent electrodepositon and annealing treatments are applied to transform the fine constituent nanocrystals into larger ones, thus considerably enhancing the electrical conductivity. The obtained CdS networks are tested as anodes in photochemical solar cells and demonstrate conversion efficiency values up to 2.00% under the illumination of one sun. After depositing an additional CdSe layer, the conversion efficiency of the structures is further increased to 2.47%.
Publisher: Wiley
Date: 21-02-2019
Abstract: Quantum dots (QDs) of lead chalcogenides (e.g. PbS, PbSe, and PbTe) are attractive near-infrared (NIR) active materials that show great potential in a wide range of applications, such as, photovoltaics (PV), optoelectronics, sensors, and bio-electronics. The surface ligand plays an essential role in the production of QDs, post-synthesis modification, and their integration to practical applications. Therefore, it is critically important that the influence of surface ligands on the synthesis and properties of QDs is well understood for their applications in various devices. In this Review we elaborate the application of colloidal synthesis techniques for the preparation of lead chalcogenide based QDs. We specifically focus on the influence of surface ligands on the synthesis of QDs and their solution-phase ligand exchange. Given the importance of lead chalcogenide QDs as potential light harvesters, we also pay particular attention to the current progress of these QDs in photovoltaic applications.
Publisher: Springer Science and Business Media LLC
Date: 30-01-2023
Publisher: Wiley
Date: 30-01-2020
Abstract: Electrochemical energy devices, such as fuel cells and metal-air batteries, convert chemical energy directly into electricity without adverse environmental impact. Attractive alternatives to expensive noble metals used in these renewable energy technologies are earth-abundant transition metal oxides. However, they are often limited by catalytic and conductive capabilities. Here reported is a spinel oxide, Co
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8CC08066F
Abstract: Low concentration tin bronze alloys show high selectivity for CO 2 electroreduction to CO, while high concentration tin bronze alloys show high selectivity for formate.
Publisher: American Chemical Society (ACS)
Date: 06-07-2023
DOI: 10.1021/JACS.3C05171
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0GC00432D
Publisher: Wiley
Date: 16-05-2018
Publisher: Wiley
Date: 13-06-2019
Abstract: Electrochemical nitrogen reduction reaction (NRR) under ambient conditions provides an avenue to produce carbon-free hydrogen carriers. However, the selectivity and activity of NRR are still hindered by the sluggish reaction kinetics. Nitrogen Vacancies on transition metal nitrides are considered as one of the most ideal active sites for NRR by virtue of their unique vacancy properties such as appropriate adsorption energy to dinitrogen molecule. However, their catalytic performance is usually limited by the unstable feature. Herein, a new 2D layered W
Publisher: Wiley
Date: 03-11-2014
Abstract: Dendritic silica micro-/nanoparticles with center-radial pore structures, a kind of newly created porous material, have attracted considerable attention owing to their unique open three-dimensional dendritic superstructures with large pore channels and highly accessible internal surface areas compared with conventional mesoporous silica nanoparticles (MSNs). They are very promising platforms for a variety of applications in catalysis and nanomedicine. In this review, their unique structural characteristics and properties are first analyzed, then novel and interesting synthesis methods associated with the possible formation mechanisms are summarized to provide material scientists some inspiration for the preparation of this kind of dendritic particles. Subsequently, a few ex les of interesting applications are presented, mainly in catalysis, biomedicine, and other important fields such as for sacrificial templates and functional coatings. The review is concluded with an outlook on the prospects and challenges in terms of their controlled synthesis and potential applications.
Publisher: Wiley
Date: 09-12-2019
Publisher: Elsevier BV
Date: 09-2008
Publisher: Elsevier BV
Date: 03-2012
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CS60425J
Abstract: Active and robust cocatalysts constructed from earth-abundant elements greatly contribute to the highly efficient, stable and cost-effective photocatalytic water splitting.
Publisher: IOP Publishing
Date: 21-08-2012
DOI: 10.1088/0957-4484/23/36/365601
Abstract: Galvanic replacement (GR) reactions involving active-metal nanoparticles (NPs) as seeds have a number of distinctive features and can produce various noble-metal nanoparticles. The oxide layer on the surfaces of such active-metal seeds may make a remarkable impact on the final products. Taking the Zn/Cu(2+) system as a model, we show that the GR reaction of pure Zn seeds with Cu(2+) ions leads to Cu nanodendrites, while oxide-covered Zn seeds result in ultrafine Cu NPs. We demonstrate here that the oxide layer does not block the GR reaction but slows down its rate. We also show that the growing Cu NPs can eventually detach from their ZnO substrate because of poor adhesion and disperse in the reaction liquid very well. Our studies provide detailed information on mechanisms of the GR reaction involving active-metal seeds, and therefore may be useful for further control of the morphology and properties of products prepared via this approach.
Publisher: Wiley
Date: 30-12-2015
Abstract: A freestanding SnO2@N-CNF film prepared by electrospinning exhibits excellent flexibility and a high surface area of 506 m(2) g(-1). When used as an anode for lithium-ion batteries, a high reversible capacity of 754 mAh g(-1) is maintained after the 300(th) cycle at 1 A g(-1) . Even when the current density increases to 5 A g(-1), the SnO2@N-CNF still delivers 245.9 mAh g(-1).
Publisher: American Chemical Society (ACS)
Date: 21-02-2019
Publisher: Wiley
Date: 17-09-2020
Publisher: Wiley
Date: 12-07-2019
Abstract: Heterogeneous electrocatalysis typically involves charge transfer between surface active sites and adsorbed species. Therefore, modulating the surface charge state of an electrocatalyst can be used to enhance performance. A series of negatively charged transition‐metal (Fe, Co, Ni, Cu,and NiCo) phosphides were fabricated by designing strong electronic coupling with hydr(oxy)oxides formed in situ. Physicochemical characterizations, together with DFT computations, demonstrate that strong electronic coupling renders transition‐metal phosphides negatively charged. This facilitates destabilization of alkaline water adsorption and dissociation to result in significantly improved H 2 evolution. Negatively charged Ni 2 P/nickel hydr(oxy)oxide for ex le exhibits a significantly low overpotential of 138 mV at 100 mA cm −2 , superior to that without strong electronic coupling and also commercial Pt/C.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.BIOMATERIALS.2014.03.051
Abstract: To create advanced functional nanocarriers for achieving excellent gene delivery performance, fluorescence label-free hybridized dendrimer-like silica nanocarriers (HPSNs-AC-PEI) were developed by using the endosomal pH and cytoplasmic glutathione (GSH) responsive autofluorescent acetaldehyde-modified-cystine (AC) to link non-toxic low molecular weight branched polyethyleneimine (PEI) onto amino-functionalized dendrimer-like silica nanoparticles with hierarchical pores (HPSNs-NH2). The specific microstructure of this hybridized nanocarrier makes it not only show low cytotoxicity and high gene loading capability, but also display high gene transfection efficiency. The cleavage of disulfide bonds caused by GSH facilitates plasmid DNA (pDNA) release. Moreover, the pH and GSH controlled gene delivery profile can be real-time tracked using the autofluorescence of HPSNs-AC-PEI.
Publisher: American Chemical Society (ACS)
Date: 11-03-2014
DOI: 10.1021/JA500432H
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2EE00162D
Abstract: Recent progress in battery recycling is critically reviewed, including closed-loop design of new batteries and recycling-oriented design of battery configurations and components, together with an appraisal of predicted future research.
Publisher: Elsevier BV
Date: 05-2015
Publisher: Elsevier BV
Date: 2018
Publisher: Wiley
Date: 27-10-2022
Abstract: Single‐atom catalysts (SACs) hold great promise for highly efficient heterogeneous catalysis, yet the practical applications require the development of high‐density active sites with flexible geometric structures. The lack of understanding in the dynamic formation process of single atoms in the host framework has been plaguing the controllable synthesis of next generation SACs. Here using Co‐based metal‐organic frameworks (MOFs) as a starting substrate, we fully elucidated the formation of high‐density Pt single atoms with inter‐site interactions in derived Co 3 O 4 host. The cation exchange process and dynamic evolution of Pt−Pt interactions, organic ligand cleavage and Pt‐oxygen coordination formation during the pyrolysis process have been unambiguously interpreted by a series of in situ/ex situ spectroscopic measurements and theoretical computation. These findings would direct the synthesis of high‐density SACs with metal‐metal interactions, which demonstrate significantly enhanced structural flexibility and catalytic properties.
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 11-2003
Publisher: American Chemical Society (ACS)
Date: 07-12-2022
DOI: 10.1021/JACS.2C11374
Publisher: Wiley
Date: 03-05-2022
Abstract: Electrocatalysts for high‐rate hydrogen evolution reaction (HER) are crucial to clean fuel production. Nitrogen‐rich 2D transition metal nitride, designated “nitridene”, has shown promising HER performance because of its unique physical/chemical properties. However, its synthesis is hindered by the sluggish growth kinetics. Here for the first time using a catalytic molten‐salt method, we facilely synthesized a V−Mo bimetallic nitridene solid solution, V 0.2 Mo 0.8 N 1.2 , with tunable electrocatalytic property. The molten‐salt synthesis reduces the growth barrier of V 0.2 Mo 0.8 N 1.2 and facilitates V dissolution via a monomer assembly, as confirmed by synchrotron spectroscopy and ex situ electron microscopy. Furthermore, by merging computational simulations, we confirm that the V doping leads to an optimized electronic structure for fast protons coupling to produce hydrogen. These findings offer a quantitative engineering strategy for developing analogues of MXenes for clean energy conversions.
Publisher: Elsevier BV
Date: 30-10-2009
DOI: 10.1016/J.JHAZMAT.2009.05.070
Abstract: Friedel's salt (3CaO x Al2O3 x CaCl2 x 10 H2O or Ca4Al2(OH)12Cl2(H2O)4) is a calcium aluminate hydrate formed by hydrating cement or concrete in seawater at a low cost. In the current study, we carefully examined the adsorption behaviors of Friedel's salt for Cr(VI) from aqueous solution at different concentrations and various initial pHs. The adsorption kinetic data are well fitted with the pseudo-first-order Lageren equation at the initial Cr(VI) concentration from 0.10 to 8.00 mM. Both the experimental and modeled data indicate that Friedel's salt can adsorb a large amount of Cr(VI) (up to 1.4 mmol Cr(VI)/g) very quickly (t1/2 = 2-3 min) with a very high efficiency (>99% Cr(VI) removal at [Cr] < 4.00 mM with 4.00 g/L of adsorbent) in the pH range of 4-10. In particular, the competitive adsorption tests show that the Cr(VI) removal efficiency is only slightly affected by the co-existence of Cl(-) and HCO3(-). The Cr(VI)-fixation stability tests show that only less than 0.2% adsorbed Cr(VI) is leaching out in water at pH 4-10 for 24 h because the adsorption/exchange of Cr(VI) with Friedel's salt leads to the formation of a new stable phase (3CaO x Al2O3 x CaCrO4 x 10 H2O). This research thus suggests that Friedel's salt is a potential cost-effective adsorbent for Cr(VI) removal in wastewater treatment.
Publisher: Wiley
Date: 24-03-2017
Publisher: American Chemical Society (ACS)
Date: 09-12-2003
DOI: 10.1021/LA0353430
Abstract: We study here the adsorption of hexane on nanoporous MCM-41 silica at 303,313, and 323 K, for various pore diameters between 2.40 and 4.24 nm. Adsorption equilibria, measured thermogravimetrically, show that all the isotherms, that are somewhat akin to those of type V, exhibit remarkably sharp capillary adsorption phase transition steps and are reversible. The position of the phase transition step gradually shifts from low to high relative pressure with an increase in the temperature as well as the pore sizes. The isosteric heats of adsorption derived from the equilibrium information using the Clapeyron equation reveal a gradual decrease with increasing adsorbed amount because of the surface heterogeneity but approach a constant value near the phase transition. A decrease in the pore size results in an increase in the isosteric heat of adsorption because of the increased dispersion forces. A simple strategy, based on the Broekhoff and De Boer adsorption theory, successfully interprets the hexane adsorption isotherms for the different pore size MCM-41 s les. The parameters of an empirical expression, used to represent the potential of interaction between the adsorbate and adsorbent, are obtained by fitting the monolayer region prior to capillary condensation and the experimental phase transition simultaneously, for some pore sizes. Subsequently, the parameters are used to predict the adsorption isotherm on other pore size s les, which showed good agreement with experimental data.
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7CC08843D
Abstract: A strategy for engineering single-crystalline nanoarrays is presented as an effective way to manipulate the catalytic activity and operational stability of NiFe-hydroxide.
Publisher: American Chemical Society (ACS)
Date: 16-04-2010
DOI: 10.1021/JP102368S
Publisher: Wiley
Date: 29-06-2010
Publisher: American Chemical Society (ACS)
Date: 14-08-2019
Publisher: Wiley
Date: 19-08-2013
Abstract: Functionalized dendrimer-like hybrid silica nanoparticles with hierarchical pores are designed and synthesized. The unique structure, large surface area, and excellent biocompability render such materials attractive nanocarriers for the advanced delivery of various sized drugs and genes simultaneously.
Publisher: Wiley
Date: 25-04-2018
Publisher: Wiley
Date: 23-03-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR06777H
Abstract: Mesoporous organosilica nanoparticles with a novel bowl-like morphology were synthesized. These nano-bowls possess uniform particle sizes around 180 nm and open cavities around 140 nm, which lead to higher loading capability for plasmid DNA than traditional silica-based nanoparticles. In vitro DNA transfection using these nano-bowls is demonstrated.
Publisher: Elsevier BV
Date: 12-2019
Publisher: American Association for the Advancement of Science (AAAS)
Date: 29-04-2022
Abstract: Single-atom catalysts (SACs) include a promising family of electrocatalysts with unique geometric structures. Beyond conventional ones with fully isolated metal sites, an emerging class of catalysts with the adjacent metal single atoms exhibiting intersite metal-metal interactions appear in recent years and can be denoted as correlated SACs (C-SACs). This type of catalysts provides more opportunities to achieve substantial structural modification and performance enhancement toward a wider range of electrocatalytic applications. On the basis of a clear identification of metal-metal interactions, this review critically examines the recent research progress in C-SACs. It shows that the control of metal-metal interactions enables regulation of atomic structure, local coordination, and electronic properties of metal single atoms, which facilitate the modulation of electrocatalytic behavior of C-SACs. Last, we outline directions for future work in the design and development of C-SACs, which is indispensable for creating high-performing new SAC architectures.
Publisher: Wiley
Date: 16-03-2023
Abstract: The electrochemical urea oxidation reaction (UOR) is an alternative to electrooxidation of water for energy–saving hydrogen (H 2 ) production. To maximize this purpose, design of catalysts for selective urea‐to‐nitrite (NO 2 – ) electrooxidation with increased electron transfer and high current is practically important. Herein, a cobalt, germanium (Co, Ge) co‐doped nickel (Ni) oxyhydroxide catalyst is reported first time that directs urea‐to‐NO 2 – conversion with a significant Faradaic efficiency of 84.9% at 1.4 V versus reversible hydrogen electrode and significantly boosts UOR activity to 448.0 mA cm −2 . Importantly, this performance is greater than for most reported Ni‐based catalysts. Based on judiciously combined synchrotron‐based measurement, in situ spectroscopy and density functional theoretical computation, significantly boosted urea‐to‐NO 2 – production results from Co, Ge co‐doping is demonstrated that optimizes electronic structure of Ni sites in which urea adsorption is altered as NO‐terminal configuration to facilitate CN cleavage for *NH formation, and thereby expedites pathway for urea to NO 2 – conversion. Findings highlight the importance of tuning intermediate adsorption behavior for design of high‐performance UOR electrocatalysts, and will be of practical benefit to a range of researchers and manufacturers in replacing conventional water electrooxidation with UOR for energy‐saving H 2 production.
Publisher: American Chemical Society (ACS)
Date: 08-10-2021
DOI: 10.1021/JACS.1C06255
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NR00663J
Abstract: The photocatalytic performance of hydrogen production is significantly accelerated by a two-dimensional Co-based metal–organic framework.
Publisher: Wiley
Date: 10-03-2021
Abstract: Compared to modern fossil‐fuel‐based refineries, the emerging electrocatalytic refinery (e‐refinery) is a more sustainable and environmentally benign strategy to convert renewable feedstocks and energy sources into transportable fuels and value‐added chemicals. A crucial step in conducting e‐refinery processes is the development of appropriate reactions and optimal electrocatalysts for efficient cleavage and formation of chemical bonds. However, compared to well‐studied primary reactions (e.g., O 2 reduction, water splitting), the mechanistic aspects and materials design for emerging complex reactions are yet to be settled. To address this challenge, herein, we first present fundamentals of heterogeneous electrocatalysis and some primary reactions, and then implement these to establish the framework of e‐refinery by coupling in situ generated intermediates (integrated reactions) or products (tandem reactions). We also present a set of materials design principles and strategies to efficiently manipulate the reaction intermediates and pathways.
Publisher: Wiley
Date: 09-2023
Publisher: American Chemical Society (ACS)
Date: 21-02-2023
DOI: 10.1021/JACS.2C13540
Publisher: Wiley
Date: 18-03-2019
Abstract: Metal–organic frameworks (MOFs) have significant potential for practical application in catalysis. However, many MOFs are shown to be sensitive to aqueous solution. This severely limits application of MOFs in electrocatalytic operations for energy production and storage. Here, a Co (II) boron imidazolate framework CoB(im) 4 (ndc) 0.5 ( BIF‐91 , im = imidazolate, ndc = 2,6‐naphthalenedicarboxylate) that is rationally designed and successfully tested for electrocatalytic application in strong alkaline (pH ≈ 14) solution is reported. In such a BIF system, the inherent carboxylate species segment large channel spaces into multiple domains in which each single channel is filled with ndc ligands through the effect of zeolite channel confinement. These ligands, with strong CH···π interaction, act as a rigid auxiliary linker to significantly enhance the structural stability of the BIF‐91 framework. Additionally, the π‐conjugated effect in BIF‐91 stabilizes dopant Fe (III) at the atomic scale to construct Fe‐immobilized BIF‐91 ( Fe@BIF‐91 ). Due to the synergistic effect between Fe (III) guest and Co (II) in the framework, the Fe@BIF‐91 acts as an active and stable electrocatalyst for the oxygen evolution reaction in alkaline solution.
Publisher: Wiley
Date: 29-11-2014
Publisher: Wiley
Date: 28-11-2016
Publisher: Wiley
Date: 02-12-2015
Publisher: Wiley
Date: 17-09-2020
Publisher: American Chemical Society (ACS)
Date: 03-07-2023
DOI: 10.1021/JACS.3C05114
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C2TA00627H
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7TA10404A
Abstract: This article critically reviews the progress and challenges in using metal-free photocatalysts made from carbon, nitrogen and phosphorus used for hydrogen production.
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.BIOMATERIALS.2011.10.001
Abstract: Template assisted fabrication of magnetic silica nanospheres with large nanopores (MSNLP) and their adsorption and delivery of nucleic acids are reported in this paper. Silica spheres with controlled particle diameter (~400 nm) and large nanopore size (13-24 nm) are prepared by using Brij56 as a template of mesopore, enabling incorporation of magnetic nanocrystals into the particles under mild neutral synthesis conditions. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and field-dependent magnetisation measurements confirm that the magnetic nanocrystals have been encapsulated into the silica spheres. The saturation magnetisation values of the resulted magnetic-silica nanocomposites are tunable by adjusting the amount of Fe(3)O(4) magnetic nanocrystals used in the synthesis process. The nitrogen sorption analysis reveals that mesopores with large pore size exist in the silica matrix. After functionalisation of the silica surface with poly-(l-lysine) (PLL), the nanoparticles show strong adsorption capacity (q(m) ranging from 10 to 22.5 μg/mg) for CpG DNA. We have further demonstrated successful delivery of miRNA into rat proximal tubular epithelial cells, facilitated by efficient cellular uptake of the nanocomposites. This work provides a convenient strategy to prepare MSNLP which can offer a versatile platform for biological applications such as simultaneous drug delivery and magnetic resonance imagining under external magnetic field.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5TA01062D
Abstract: Nitrogen doping into graphdiyne leads to a reduced H 2 diffusion barrier and hence an enhanced hydrogen purification capability.
Publisher: Elsevier BV
Date: 08-1999
Publisher: Wiley
Date: 31-01-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3RA45995K
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA01903K
Abstract: Simple methods for fabricating highly active and stable interfacial bifunctional electrocatalysts for water electrolysis are essential for hydrogen production.
Publisher: Wiley
Date: 04-03-2019
Abstract: The practical scale-up of renewable energy technologies will require catalysts that are more efficient and durable than present ones. This is, however, a formidable challenge that will demand a new capability to tailor the electronic structure. Here, an original electronic structure tailoring of CoO by Ni and Zn dual doping is reported. This changes it from an inert material into one that is highly active for the hydrogen evolution reaction (HER). Based on combined density functional theory calculations and cutting-edge characterizations, it is shown that dual Ni and Zn doping is responsible for a highly significant increase in HER activity of the host oxide. That is, the Ni dopants cluster around surface oxygen vacancy of the host oxide and provide an ideal electronic surface structure for hydrogen intermediate binding, while the Zn dopants distribute inside the host oxide and modulate the bulk electronic structure to boost electrical conduction. As a result, the dual-doped Ni, Zn CoO nanorods achieve current densities of 10 and 20 mA cm
Publisher: Wiley
Date: 03-03-2019
Abstract: 2D metal-organic frameworks (MOFs) have been widely investigated for electrocatalysis because of their unique characteristics such as large specific surface area, tunable structures, and enhanced conductivity. However, most of the works are focused on oxygen evolution reaction. There are very limited numbers of reports on MOFs for hydrogen evolution reaction (HER), and generally these reported MOFs suffer from unsatisfactory HER activities. In this contribution, novel 2D Co-BDC/MoS
Publisher: Wiley
Date: 23-03-2018
Abstract: Lamellar membranes show exceptional molecular permeation properties of key importance for many applications. However, their design and development need the construction of regular and straight interlayer channels and the establishment of corresponding transport rate equation. The fabrication of a uniformly lamellar membrane is reported using double-layered Ti
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NJ03125D
Abstract: Microwave irradiation was adopted to activate gold nanoparticles, which catalysed the growth of monocrystal CdSe nanowires in solution.
Publisher: Elsevier BV
Date: 09-2000
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1EE02021H
Abstract: The working principles of interphase strategies to enhance Zn reversibility are discussed. The effectiveness evaluation techniques, including electrochemical methods, characterization measurements, and computational simulations, are proposed.
Publisher: Wiley
Date: 02-12-2015
Abstract: Free-standing flexible films, constructed from two-dimensional graphitic carbon nitride and titanium carbide (with MXene phase) nanosheets, display outstanding activity and stability in catalyzing the oxygen-evolution reaction in alkaline aqueous system, which originates from the Ti-N(x) motifs acting as electroactive sites, and the hierarchically porous structure with highly hydrophilic surface. With this excellent electrocatalytic ability, comparable to that of the state-of-the-art precious-/transition-metal catalysts and superior to that of most free-standing films reported to date, they are directly used as efficient cathodes in rechargeable zinc-air batteries. Our findings reveal that the rational interaction between different two-dimensional materials can remarkably promote the oxygen electrochemistry, thus boosting the entire clean energy system.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3EE42383B
Publisher: Springer Science and Business Media LLC
Date: 25-10-2019
DOI: 10.1038/S41467-019-12773-7
Abstract: Most fundamental studies of electrocatalysis are based on the experimental and simulation results obtained for bulk model materials. Some of these mechanistic understandings are inapplicable for more active nanostructured electrocatalysts. Herein, considering the simplest and most typical electrocatalytic process, the hydrogen evolution reaction, an alternative reaction mechanism is proposed for nanomaterials based on the identification of a new intermediate, which differs from those commonly known for the bulk counterparts. In-situ Raman spectroscopy and electrochemical thermal/kinetic measurements were conducted on a series of nanomaterials under different conditions. In high-pH electrolytes with negligible hydronium (H 3 O + ) concentration in bulk phase, massive H 3 O + intermediates are found generating on the catalytic surface during water dissociation and hydrogen adsorption processes. These H 3 O + intermediates create a unique acid-like local reaction environment on nanostructured catalytic surfaces and cut the energy barrier of the overall reaction. Such phenomena on nanostructured electrocatalysts explain their widely observed anomalously high activity under high-pH conditions.
Publisher: Wiley
Date: 26-03-2018
Abstract: Exploiting high-performance, robust, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is crucial for electrochemical energy storage and conversion technologies. Engineering the interfacial structure of hybrid catalysts often induces synergistically enhanced electrocatalytic performance. Herein, a new strongly coupled heterogeneous catalyst with proper interfacial structures, i.e., CoO nanoclusters decorated on CoFe layered double hydroxides (LDHs) nanosheets, is prepared via a simple one-step pulsed laser ablation in liquid method. Thorough spectroscopic characterizations reveal that strong chemical couplings at the hybrid interface trigger charge transfer from Co
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6NR06961D
Abstract: Developing low cost, highly active and stable electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) using the same electrolyte has remained a major challenge. Herein, we report a novel and robust material comprised of nickel-cobalt nanoparticles coated on a porous nitrogen-doped carbon (NC) thin film synthesized via a two-step pulsed laser deposition technique. The optimized s le (Ni
Publisher: American Association for the Advancement of Science (AAAS)
Date: 05-10-2018
Abstract: Atomic-level structure engineering potentially revolutionizes the design of capacitive oxide materials.
Publisher: Wiley
Date: 16-02-2016
Abstract: A universal technique has been proposed to sort two-dimensional (2D) sub-nanometer thin crystals (manganese dioxide MnO2 and molybdenum disulfide MoS2 ) according to their lateral dimensions. This technique is based on tuning the zeta potential of their aqueous dispersions which induces the selective sedimentation of large-sized 2D crystals and leaves the small-sized counterparts in suspension. The electrocatalytic properties of as-obtained 2D ultrathin crystals are strongly dependent on their lateral size. As a proof-of-concept study, the small-sized MnO2 nanocrystals were tested as the electrocatalysts for the urea-oxidation reaction (UOR), which showed outstanding performance in both half reaction and full electrolytic cell. A mechanism study reveals the enhanced performance is associated with the remarkable structural properties of MnO2 including ultrathin (ca. 0.95 nm), laterally small-sized (50-200 nm), and highly exposed active centers.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CS00470A
Abstract: This review provides insights into theoretical and experimental electrochemistry toward a better understanding of a series of key energy conversion reactions.
Publisher: American Chemical Society (ACS)
Date: 26-08-2019
Publisher: American Chemical Society (ACS)
Date: 02-02-2009
DOI: 10.1021/JP810112C
Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B819379G
Publisher: Wiley
Date: 22-11-2022
Abstract: Efficient catalyst design is important for lean‐electrolyte sulfur reduction in Li−S batteries. However, most of the reported catalysts were focused on catalyst‐polysulfide interactions, and generally exhibit high activity only with a large excess of electrolyte. Herein, we proposed a general rule to boost lean‐electrolyte sulfur reduction by controlling the catalyst‐solvent interactions. As evidenced by synchrotron‐based analysis, in situ spectroscopy and theoretical computations, strong catalyst‐solvent interaction greatly enhances the lean‐electrolyte catalytic activity and battery stability. Benefitting from the strong interaction between solvent and cobalt catalyst, the Li−S battery achieves stable cycling with only 0.22 % capacity decay per cycle with a low electrolyte/sulfur mass ratio of 4.2. The lean‐electrolyte battery delivers 79 % capacity retention compared with the battery with flooded electrolyte, which is the highest among the reported lean‐electrolyte Li−S batteries.
Publisher: American Chemical Society (ACS)
Date: 30-05-2019
DOI: 10.1021/JACS.9B03811
Abstract: The lack of chemical understanding and efficient catalysts impedes the development of electrocatalytic nitrogen reduction reaction (eNRR) for ammonia production. In this work, we employed density functional theory calculations to build up a picture (activity trends, electronic origins, and design strategies) of single-atom catalysts (SACs) supported on nitrogen-doped carbons as eNRR electrocatalysts. To construct such a picture, this work presents systematic studies of the eNRR activity of SACs covering 20 different transition metal (TM) centers coordinated by nitrogen atoms contained in three types of nitrogen-doped carbon substrates, which gives 60 SACs. Our study shows that the intrinsic activity trends could be established on the basis of the nitrogen adatom adsorption energy (Δ E
Publisher: Wiley
Date: 30-01-2017
Publisher: American Chemical Society (ACS)
Date: 17-11-2017
Abstract: Developing efficient electrocatalysts consisting of earth-abundant elements for oxygen evolution reaction (OER) is crucial for energy devices and technologies. Herein, we report self-supported highly porous nitrogen-doped graphene foam synthesized through the electrochemical expansion of carbon-fiber paper and subsequent nitrogen plasma treatment. A thorough characterization, such as electron microscopy and synchrotron-based near-edge X-ray absorption fine structure, indicates the well-developed porous structures featuring homogeneously doped nitrogen heteroatoms. These merits ensure enriched active sites, an enlarged active surface area, and improved mass/electron transport within the continuous graphene framework, thus leading to an outstanding capability toward electrocatalyzing OER in alkaline media, even competitive with the state-of-the-art noble-/transition-metal and nonmetal electrocatalysts reported to date, from the perspectives of the sharp onset potential, a small Tafel slope, and remarkable durability. Furthermore, a rechargeable Zn-air battery with this self-supported electrocatalyst directly used as the air cathode renders a low charge/discharge overpotential and considerable life span. The finding herein suggests that a rational methodology to synthesize graphene-based materials can significantly enhance the oxygen electrocatalysis, thereby promoting the overall performance of the energy-related system.
Publisher: Wiley
Date: 26-06-2014
Abstract: Gene therapy presents a unique opportunity for the treatment of genetic diseases, but the lack of multifunctional delivery systems has hindered its clinical applications. Here, a new delivery vector, autofluorescent polyethyleneimine (PEI) nanogels, for highly efficient and traceable gene delivery is developed. Different from commercial high-molecular-weight PEI, the cationic nanogels are noncytotoxic and able to be fragmented due to their unique intracellular microenvironment-responsive structures. The biodegradable nanogels can effectively load plasmid DNA (pDNA), and the self-assembled polyplexes can be cleaved after cellular uptake to improve gene transfection efficiency. Most importantly, the nanogels and the nanogel DNA polyplexes are autofluorescent. The fluorescence is stable in blood plasma and responsive to the intracellular microenvironment. The breakup of the nanogels or polyplexes leads to the loss of fluorescence, and thus the gene delivery and carrier biodegradation processes can be monitored. The reported multifunctional system demonstrates excellent biocompatibility, high transfection efficiency, responsive biodegradability, controlled gene release, label-free and simultaneous fluorescence tracking, which will provide a new platform for future scientific investigation and practical implications in gene therapy.
Publisher: Springer Science and Business Media LLC
Date: 24-08-2020
Publisher: Elsevier BV
Date: 04-2007
DOI: 10.1016/J.JCIS.2006.12.052
Abstract: We report the preparation and characterization of a novel nanocomposite adsorbent for anionic dye removal. The nanocomposite adsorbent was prepared by heterocoagulation of delaminated bentonite and layered double hydroxide (LDH) colloids. The effects of preparation conditions, LDH loading, particle size, and calcination temperature of the modified material on the physicochemical properties of this composite adsorbent have been investigated. The optimal conditions for best Reactive Yellow 2 (RY2) dye removal efficiency are a weight ratio of LDH to bentonite of 1:1, LDH particle size 100 nm, and calcination temperature 673 K. The adsorption equilibrium data can be fitted well by the widely accepted adsorption isotherm models.
Publisher: American Chemical Society (ACS)
Date: 19-03-2018
DOI: 10.1021/ACS.CHEMREV.7B00689
Abstract: Over the past few decades, the design and development of advanced electrocatalysts for efficient energy conversion technologies have been subjects of extensive study. With the discovery of graphene, two-dimensional (2D) nanomaterials have emerged as some of the most promising candidates for heterogeneous electrocatalysts due to their unique physical, chemical, and electronic properties. Here, we review 2D-nanomaterial-based electrocatalysts for selected electrocatalytic processes. We first discuss the unique advances in 2D electrocatalysts based on different compositions and functions followed by specific design principles. Following this overview, we discuss various 2D electrocatalysts for electrocatalytic processes involved in the water cycle, carbon cycle, and nitrogen cycle from their fundamental conception to their functional application. We place a significant emphasis on different engineering strategies for 2D nanomaterials and the influence these strategies have on intrinsic material performance, such as electronic properties and adsorption energetics. Finally, we feature the opportunities and challenges ahead for 2D nanomaterials as efficient electrocatalysts. By considering theoretical calculations, surface characterization, and electrochemical tests, we describe the fundamental relationships between electronic structure, adsorption energy, and apparent activity for a wide variety of 2D electrocatalysts with the goal of providing a better understanding of these emerging nanomaterials at the atomic level.
Publisher: Wiley
Date: 11-07-2023
Abstract: Obtaining partial methane oxidation reaction (MOR) with various oxygenates via a mild electrochemical method is practically difficult because of activation of stable C─H bond and consequent reaction pathway regulation. Here, a real‐time tandem MOR with cascaded plasma and electrocatalysis to activate and convert the methane (CH 4 ) synergistically is reported for the first time. Boosted CH 4 conversion is demonstrated toward value‐added products including, alcohols, carboxylates, and ketone via use of commercial Pd‐based electrocatalysts. Compared with hash industrial processes, a mild condition, that is, anode potential 1.0 V versus RHE (reversible hydrogen electrode) is used that mitigates overoxidation of oxygenates and obviates competing reaction(s). One evidence that Pd(II) sites and surface adsorbed hydroxyls are important in facilitating activated‐CH 4 species conversion, and establish a reaction mechanism for conversion(s) that involves coupling reactions between adsorbed hydroxyls, carbon monoxide and C 1 /C 2 alkyls. One conclude that pre‐activation is important in boosting electrochemical partial MOR under mild conditions and will be of benefit in the development of sustainable CH 4 conversion technology.
Publisher: American Chemical Society (ACS)
Date: 25-10-2008
DOI: 10.1021/ES801458V
Abstract: Nano-Au/Co3O4 catalyst with high gold loading was found to be a good catalytic material for the elimination of trace ethylene (ppb) at ambient conditions. The gold nanoparticles dispersed on the support nano-Co3O4 surface contribute to this high activity at room temperature. The relatively rapid deactivation trend was observed under high concentrations of ethylene (1000 ppm), because coke deposits were present on the catalyst surface during the reaction process. This type of nano-gold catalytic material shows great potential as a meaningfully environmental catalyst, particularly for indoor environmental control of trace ethylene (ppb) and keeping fruits fresh during warehouse storage.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CC04776A
Abstract: A robust porous N-carbon supported cobalt (oxide) film has been developed by pulsed laser deposition as a highly efficient OER electrode.
Publisher: Wiley
Date: 02-10-2015
Publisher: Elsevier BV
Date: 04-2014
DOI: 10.1016/J.IJPHARM.2014.01.037
Abstract: Amino functionalised mesoporous silica nanoparticles (AM-41) have been identified as a promising vaccine delivery material. The capacity of AM-41 to stabilise vaccine components at ambient temperature (23-27°C) was determined by adsorbing the model antigen ovalbumin (OVA) to AM-41 particles (OVA-41). The OVA-41 was successfully freeze-dried using the excipients 5% trehalose and 1% PEG8000. The immunological activity of OVA and the nanoparticle structure were maintained following two months storage at ambient temperature. The results of immunisation studies in mice with reconstituted OVA-41 demonstrated the induction of humoral and cell-meditated immune responses. The capacity of AM-41 particles to facilitate ambient storage of vaccine components without the loss of immunological potency will underpin the further development of this promising vaccine delivery platform.
Publisher: Wiley
Date: 21-12-2020
Publisher: American Chemical Society (ACS)
Date: 22-09-2014
DOI: 10.1021/JA5082553
Abstract: Hybrid porous nanowire arrays composed of strongly interacting Co3O4 and carbon were prepared by a facile carbonization of the metal-organic framework grown on Cu foil. The resulting material, possessing a high surface area of 251 m(2) g(-1) and a large carbon content of 52.1 wt %, can be directly used as the working electrode for oxygen evolution reaction without employing extra substrates or binders. This novel oxygen evolution electrode can smoothly operate in alkaline solutions (e.g., 0.1 and 1.0 M KOH), affording a low onset potential of 1.47 V (vs reversible hydrogen electrode) and a stable current density of 10.0 mA cm(-2) at 1.52 V in 0.1 M KOH solution for at least 30 h, associated with a high Faradaic efficiency of 99.3%. The achieved ultrahigh oxygen evolution activity and strong durability, with superior performance in comparison to the state-of-the-art noble-metal/transition-metal and nonmetal catalysts, originate from the unique nanowire array electrode configuration and in situ carbon incorporation, which lead to the large active surface area, enhanced mass/charge transport capability, easy release of oxygen gas bubbles, and strong structural stability. Furthermore, the hybrid Co3O4-carbon porous nanowire arrays can also efficiently catalyze oxygen reduction reaction, featuring a desirable four-electron pathway for reversible oxygen evolution and reduction, which is potentially useful for rechargeable metal-air batteries, regenerative fuel cells, and other important clean energy devices.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9EE00950G
Abstract: Crystalline–amorphous phase boundary engineering can be an effective strategy to develop cost-effective and high-performance electrocatalysts for water splitting.
Publisher: Wiley
Date: 24-07-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C3CC47665K
Abstract: A three-dimensional framework promoter of graphene-MnO2 was fabricated to enhance the catalytic properties of NiCo2O4. The as-resultant graphene-MnO2-NiCo2O4 hybrid material features a number of remarkable structural properties such as well-developed pores, 3D conductive networks and strong coupling synergistic effects, rendering it an outstanding catalyst for electrocatalytic oxygen evolution.
Publisher: Wiley
Date: 10-03-2016
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7CC05466A
Abstract: The coupling of few-layer phosphorene nano-sheets with Zn x Cd 1−x S nano-particles greatly improved the visible-light photocatalytic H 2 -production activity.
Publisher: Wiley
Date: 08-10-2018
Abstract: The development of 1D nanostructures with enhanced material properties has been an attractive endeavor for applications in energy and environmental fields, but it remains a major research challenge. Herein, this work demonstrates a simple, gel-derived method to synthesize uniform 1D elongated sub-nanotubes with an anatase/bronze TiO
Publisher: Wiley
Date: 13-02-2017
Abstract: Manganese-based oxides have exhibited high promise as noncoinage alternatives to Pt/C for catalyzing oxygen reduction reaction (ORR) in basic solution and a mix of Mn
Publisher: Wiley
Date: 09-2015
Publisher: Elsevier BV
Date: 03-2021
Publisher: Springer Science and Business Media LLC
Date: 30-01-2014
Publisher: Elsevier BV
Date: 11-2015
Publisher: American Chemical Society (ACS)
Date: 07-08-2015
Publisher: Wiley
Date: 14-07-2015
Publisher: American Chemical Society (ACS)
Date: 28-01-2022
DOI: 10.1021/JACS.1C12212
Abstract: Copper is the only metal catalyst that can perform the electrocatalytic CO
Publisher: Wiley
Date: 07-04-2020
Abstract: Single‐atom catalysts (SACs) have great potential in electrocatalysis. Their performance can be rationally optimized by tailoring the metal atoms, adjacent coordinative dopants, and metal loading. However, doing so is still a great challenge because of the limited synthesis approach and insufficient understanding of the structure–property relationships. Herein, we report a new kind of Mo SAC with a unique O,S coordination and a high metal loading over 10 wt %. The isolation and local environment was identified by high‐angle annular dark‐field scanning transmission electron microscopy and extended X‐ray absorption fine structure. The SACs catalyze the oxygen reduction reaction (ORR) via a 2 e − pathway with a high H 2 O 2 selectivity of over 95 % in 0.10 m KOH. The critical role of the Mo single atoms and the coordination structure was revealed by both electrochemical tests and theoretical calculations.
Publisher: Wiley
Date: 02-01-2019
Abstract: Room-temperature sodium-sulfur (RT-Na/S) batteries hold significant promise for large-scale application because of low cost of both sodium and sulfur. However, the dissolution of polysulfides into the electrolyte limits practical application. Now, the design and testing of a new class of sulfur hosts as transition-metal (Fe, Cu, and Ni) nanoclusters (ca. 1.2 nm) wreathed on hollow carbon nanospheres (S@M-HC) for RT-Na/S batteries is reported. A chemical couple between the metal nanoclusters and sulfur is hypothesized to assist in immobilization of sulfur and to enhance conductivity and activity. S@Fe-HC exhibited an unprecedented reversible capacity of 394 mAh g
Publisher: American Association for the Advancement of Science (AAAS)
Date: 23-06-2023
Abstract: The trade-off between activity and stability of oxygen evolution reaction (OER) catalysts in proton exchange membrane water electrolyzer (PEMWE) is challenging. Crystalline IrO 2 displays good stability but exhibits poor activity amorphous IrO x exhibits outstanding activity while sacrificing stability. Here, we combine the advantages of these two materials via a lattice water–incorporated iridium oxide (IrO x · n H 2 O) that has short-range ordered structure of hollandite-like framework. We confirm that IrO x · n H 2 O exhibits boosted activity and ultrahigh stability of hours (~8 months) with a record-high stability number of 1.9 × 10 7 n oxygen n Ir −1 . We evidence that lattice water is active oxygen species in sustainable and rapid oxygen exchange. The lattice water–assisted modified OER mechanism contributes to improved activity and concurrent stability with no apparent structural degradation, which is different to the conventional adsorbate evolution mechanism and lattice oxygen mechanism. We demonstrate that a high-performance PEMWE with IrO x · n H 2 O as anode electrocatalyst delivers a cell voltage of 1.77 V at 1 A cm −2 for 600 hours (60°C).
Publisher: Wiley
Date: 28-09-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CP50734C
Abstract: Production of hydrogen from photocatalytic water splitting has become an attractive research area due to the possibility of converting solar energy into green chemical energy. In this study, novel NiS nanoparticle (NP) modified CdS nanorod (NR) p-n junction photocatalysts were prepared by a simple two-step hydrothermal method. Even without the Pt co-catalyst, the as-prepared NiS NP-CdS NR s les exhibited enhanced visible-light photocatalytic activity and good stability for H2-production. The optimal NiS loading content was determined to be 5 mol%, and the corresponding H2-production rate reached 1131 μmol h(-1) g(-1), which is even higher than that of the optimized Pt-CdS NRs. It is believed that the assembly of p-type NiS NPs on the surface of n-type CdS NRs could form a large number of p-n junctions, which could effectively reduce the recombination rates of electrons and holes, thus greatly enhancing the photocatalytic activity. This work not only shows a possibility for the utilization of low cost NiS nanoparticles as a substitute for noble metals (such as Pt) in the photocatalytic H2-production but also provides a new insight into the design and fabrication of other new p-n junction photocatalysts for enhancing H2-production activity.
Publisher: Wiley
Date: 24-03-2017
Abstract: Engineering high-energy interfacial structures for high-performance electrocatalysis is achieved by chemical coupling of active CoO nanoclusters and high-index facet Mn
Publisher: Wiley
Date: 17-07-2014
Abstract: An Fe-N-decorated hybrid material of carbon nanotubes (CNTs) grown in situ from porous carbon microblocks is designed and constructed. This material successfully combines the desirable merits for oxygen reduction reaction (ORR), such as highly active Fe-N species, good conductivity, large pore size, and sufficient surface area. These structural advantages give this low-priced material an outstanding catalytic performance for ORR closely comparable with Pt/C of the same quantity.
Publisher: Wiley
Date: 28-12-2016
Publisher: American Chemical Society (ACS)
Date: 12-10-2020
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.JCIS.2009.07.041
Abstract: With initial aging at low temperature for enough time, silicas with large mesoporosity were synthesized using triblock copolymer as template agent under weak acidities. SBA-15 with periodic mesostructure and short mesochannels could be synthesized at pH 2.5-3.0 within weak acidity range, and the surface areas, pore diameters and pore volumes reached up to ca. 1000m(2)/g, 8.8nm and 2.0cm(3)/g, respectively, which were significantly higher than those of the conventional SBA-15 synthesized under strong acidities. Mesoporous silica with wormhole structure and abundant textural porosity was formed at pH approximately 3.5. The increased hydrophobic volume of the copolymer micelles at elevated pH values was responsible for the enlargement of mesoporosity in the products. The materials synthesized under weak acidities showed lower hexagonal ordering in comparison to the general SBA-15 synthesized under strong acidities because the decreased hydronium ion concentration induced relatively weaker assembly forces during the synthesis. Nonetheless, the short mesochannels and large pore diameter in the products might be beneficial to some applications in which fast diffusion of molecules is required.
Publisher: Elsevier BV
Date: 07-2019
Publisher: Wiley
Date: 25-04-2017
Abstract: Blueshift of optical absorption and corresponding widening of the bandgap is a fundamental problem with 2D carbon nitride nanosheets (CNNS). An additional problem is low quantum yields (<9%) due to higher loss of absorbed photons. These problems impose a significant restriction to photocatalytic performance of CNNS. Therefore, the synthesis of narrow bandgap CNNS with high quantum efficiency is of pressing research importance. This contribution reports melem-derived narrow bandgap CNNS with a record-low bandgap of 2.45 eV. The narrowing in bandgap comes with improved optical absorption and use of visible-light photons together with excellent charge transport dynamics. This is demonstrated by a record high hydrogen evolution rate of 863 µmol h
Publisher: Wiley
Date: 29-09-2015
Publisher: Wiley
Date: 12-01-2011
Publisher: Wiley
Date: 17-07-2017
Publisher: Wiley
Date: 20-09-2007
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CC04471G
Abstract: A simple approach was proposed to synthesize three types of ellipsoidal hollow nanostructures whose shells are assembled from anatase TiO(2) nanosheets (NSs) with exposed (001) facets. Among them, ellipsoid Fe(3)O(4)@TiO(2)-NS nanorattles can be readily generated as a magnetically separable photocatalyst with enhanced activity through in situ reduction of the α-Fe(2)O(3) core.
Publisher: American Chemical Society (ACS)
Date: 02-01-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC43338B
Abstract: The hybrid material composed of Mn3O4 nanoparticles on nitrogen-doped graphene was prepared via a solvothermal process and investigated for the first time as a catalyst for oxygen reduction reaction (ORR). Its high ORR activity, excellent durability and tolerance to methanol make this hybrid material a promising candidate for highly efficient ORR in fuel cells and metal-air batteries.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CS00163H
Abstract: This work constructively reviewed and predicted the surface strategies for catalytic CO 2 reduction with 2D material, nanocluster and single-atom catalysts
Publisher: Wiley
Date: 30-11-2018
Abstract: Owing to the excellent physical properties of metal nitrides such as metallic conductivity and pseudocapacitance, they have recently attracted much attention as competitive materials for high-performance supercapacitors (SCs). However, the voltage window for metal nitride-based symmetric SCs is limited (0.6-0.8 V) in aqueous electrolyte due to the oxidation at high negative potentials. In this respect, ultra-small tungsten nitride particles onto the phosphorous modified carbon fabric (W
Publisher: Wiley
Date: 04-02-2019
Abstract: Effective electrocatalysts are required for the CO
Publisher: Wiley
Date: 09-01-2023
Abstract: The design of heterogeneous catalysts is necessarily surface‐focused, generally achieved via optimization of adsorption energy and microkinetic modelling. A prerequisite is to ensure the adsorption energy is physically meaningful is the stable existence of the conceived active‐site structure on the surface. The development of improved understanding of the catalyst surface, however, is challenging practically because of the complex nature of dynamic surface formation and evolution under in‐situ reactions. We propose therefore data‐driven machine‐learning (ML) approaches as a solution. In this Minireview we summarize recent progress in using machine‐learning to search and predict (meta)stable structures, assist operando simulation under reaction conditions and micro‐environments, and critically analyze experimental characterization data. We conclude that ML will become the new norm to lower costs associated with discovery and design of optimal heterogeneous catalysts.
Publisher: Wiley
Date: 18-11-2017
Abstract: A robust solution phase ligand exchange system for lead sulfide (PbS) quantum dots (QDs) in the presence of Pb-thiolate ligands is presented that can better preserve the excitonic absorption and emission features as compared to the conventional ligands. The photoluminescence after ligand exchange of PbS QDs with Pb-thiolate ligand is preserved up to 78% of the original oleate capped PbS QDs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B925201K
Publisher: Wiley
Date: 19-05-2016
Abstract: A novel type of magnetic core-shell silica nanoparticles is developed for small interfering RNA (siRNA) delivery. These nanoparticles are fabricated by coating super-paramagnetic magnetite nanocrystal clusters with radial large-pore mesoporous silica. The amine functionalized nanoparticles have small particle sizes around 150 nm, large radial mesopores of 12 nm, large surface area of 411 m(2) g(-1) , high pore volume of 1.13 cm(3) g(-1) and magnetization of 25 emu g(-1) . Thus, these nanoparticles possess both high loading capacity of siRNA (2 wt%) and strong magnetic response under an external magnetic field. An acid-liable coating composed of tannic acid can further protect the siRNA loaded in these nanoparticles. The coating also increases the dispersion stability of the siRNA-loaded carrier and can serve as a pH-responsive releasing switch. Using the magnetic silica nanoparticles with tannic acid coating as carriers, functional siRNA has been successfully delivered into the cytoplasm of human osteosarcoma cancer cells in vitro. The delivery is significantly enhanced with the aid of the external magnetic field.
Publisher: Wiley
Date: 11-10-2023
Publisher: American Chemical Society (ACS)
Date: 08-01-2015
DOI: 10.1021/NN506701X
Abstract: Pt-free electrocatalysts for hydrogen evolution reaction (HER) with high activity and low price are desirable for many state-of-the-art renewable energy devices, such as water electrolysis and photoelectrochemical water splitting cells. However, the design and fabrication of such materials remain a significant challenge. This work reports the preparation of a flexible three-dimensional (3D) film by integrating porous C3N4 nanolayers with nitrogen-doped graphene sheets, which can be directly utilized as HER catalyst electrodes without substrates. This nonmetal electrocatalyst has displayed an unbeatable HER performance with a very positive onset-potential close to that of commercial Pt (8 mV vs 0 mV of Pt/C, vs RHE @ 0.5 mA cm(-2)), high exchange current density of 0.43 mA cm(-2), and remarkable durability (seldom activity loss >5000 cycles). The extraordinary HER performance stems from strong synergistic effect originating from (i) highly exposed active sites generated by introduction of in-plane pores into C3N4 and exfoliation of C3N4 into nanosheets, (ii) hierarchical porous structure of the hybrid film, and (iii) 3D conductive graphene network.
Publisher: Springer Science and Business Media LLC
Date: 03-01-2017
DOI: 10.1038/NCOMMS13907
Abstract: Scalable and sustainable solar hydrogen production through photocatalytic water splitting requires highly active and stable earth-abundant co-catalysts to replace expensive and rare platinum. Here we employ density functional theory calculations to direct atomic-level exploration, design and fabrication of a MXene material, Ti 3 C 2 nanoparticles, as a highly efficient co-catalyst. Ti 3 C 2 nanoparticles are rationally integrated with cadmium sulfide via a hydrothermal strategy to induce a super high visible-light photocatalytic hydrogen production activity of 14,342 μmol h −1 g −1 and an apparent quantum efficiency of 40.1% at 420 nm. This high performance arises from the favourable Fermi level position, electrical conductivity and hydrogen evolution capacity of Ti 3 C 2 nanoparticles. Furthermore, Ti 3 C 2 nanoparticles also serve as an efficient co-catalyst on ZnS or Zn x Cd 1− x S. This work demonstrates the potential of earth-abundant MXene family materials to construct numerous high performance and low-cost photocatalysts hotoelectrodes.
Publisher: Wiley
Date: 02-03-2012
Abstract: Honeycomb catalysis: a facile oxygen reduction reaction has been observed on a graphitic C(3)N(4)/carbon catalyst with three-dimensional interconnected macropores (see picture with SiO(2) template). This material not only shows catalytic activity that is comparable to that of commercial Pt/C, but also has much higher organic-fuel tolerance and long-term stability.
Publisher: Wiley
Date: 16-12-2022
Abstract: We demonstrate a widely applicable method to alter the adsorption configuration of multi‐carbon containing reactants by no catalyst engineering but simply adjusting the local reaction environment of the catalyst surface. Using electrocatalytic acetone to propane hydrogenation (APH) as a model reaction and common commercial Pt/Pt‐based materials as catalysts, we found local H + concentration can significantly influence the adsorption mode of acetone reactant, for ex le, in vertical or flat mode, and target product selectivity. Electrocatalytic measurement combined with in situ spectroscopic characterizations reveals that the vertically adsorbed acetone is favorable for propane production while the flatly adsorbed mode suppresses the reaction. DFT calculations indicate that the H coverage on catalyst surface plays a decisive role in the adsorption configuration of acetone. The increased local acidity can facilitate the adsorption configuration of acetone from flat to vertical mode and suppress the competing hydrogen evaluation reaction, which consequently enhances the APH selectivity.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5CC00995B
Abstract: An Fe/N co-doped graphitic carbon bulb synthesized at low temperature shows excellent oxygen reduction reaction performance.
Publisher: American Chemical Society (ACS)
Date: 28-09-2010
DOI: 10.1021/AM100351K
Abstract: We report the synthesis of carbon nanotubes (CNTs)/mesostructured silica core-shell nanowires via an interfacial surfactant templating approach. The nanowires possess perpendicularly aligned and uniform accessible mesopores, high surface area and large pore volume. When dimethyl sulfoxide reductase (DMSOR) enzyme is immobilized on the core-shell nanowires, the complex can enhance the electrical communication between the active sites of the enzyme and the electrode surface in the presence of a mediator. The unique properties of the CNTs and the uniform accessible mesopores of the nanowires have made this material promising in the applications as carbon nanotubes field-effect transistors, electrochemical detection, and biosensors.
Publisher: Wiley
Date: 25-02-2020
Publisher: WORLD SCIENTIFIC
Date: 04-2000
Publisher: Wiley
Date: 20-08-2013
Abstract: A novel nitrogen doped hybrid material composed of in situ-formed graphene natively grown on hierarchical ordered porous carbon is prepared, which successfully combines the advantages of both materials, such as high surface area, high mass transfer, and high conductivity. The outstanding structural properties of the resultant material render it an excellent metal-free catalyst for electrochemical oxygen reduction.
Publisher: American Chemical Society (ACS)
Date: 25-04-2006
DOI: 10.1021/JA0607537
Abstract: Periodic mesoporous organosilica (PMO) hollow spheres with tunable wall thickness have been successfully synthesized by a new vesicle and a liquid crystal "dual templating" mechanism, which may be applicable for drug and DNA delivery systems, biomolecular encapsulation, as well as nanoreactors for conducting biological reactions at the molecular levels.
Publisher: Elsevier BV
Date: 07-2004
Publisher: Wiley
Date: 19-07-2017
Abstract: Transitional metals are widely used as co-catalysts boosting photocatalytic H
Publisher: American Chemical Society (ACS)
Date: 31-10-2012
DOI: 10.1021/ES303069J
Abstract: Graphitized carbons with mesoporous and macroporous structures were synthesized by a facile template-catalysis procedure using resorcinol and formaldehyde as carbon precursors and particulate hydrated metal oxides as both template and catalyst precursors. The materials were used as novel adsorbents for low-concentration benzene vapor. Furthermore, on the basis of the good electrical conductivities associated with the graphitized structures, an electrothermal desorption technique, which involved passing electric currents through the adsorbents to generate Joule heat, was employed to regenerate the saturated adsorbents and produce enriched benzene vapors. In comparison to microporous activated carbon, the porous graphitized carbons could afford a much quicker and more efficient regeneration by electrothermal desorption technique due to their enhanced conductivity and larger pore sizes. In addition, the concentration of the desorbed organics could be controlled by adjusting the applied voltages, which might be interesting for practical secondary treatment. It is promising that the joint utilization of porous graphitized carbon adsorbents and electrothermal desorption technique might develop effective and energy-saving processes for VOCs removal.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5TA10194H
Abstract: We introduce a three-step method (co-polymerization, surface activation and exfoliation) for the first time to synthesize sub-nanometer-thin carbon nitride nanosheets as highly efficient hydrogen evolution photocatalysts.
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3CS00445G
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA13299D
Publisher: Wiley
Date: 18-01-2011
Publisher: Wiley
Date: 08-01-2015
Abstract: Three-dimensional (3D) nanometal films serving as current collectors have attracted much interest recently owing to their promising application in high-performance supercapacitors. In the process of the electrochemical reaction, the 3D structure can provide a short diffusion path for fast ion transport, and the highly conductive nanometal may serve as a backbone for facile electron transfer. In this work, a novel polypyrrole (PPy) shell@3D-Ni-core composite is developed to enhance the electrochemical performance of conventional PPy. With the introduction of a Ni metal core, the as-prepared material exhibits a high specific capacitance (726 F g(-1) at a charge/discharge rate of 1 A g(-1)), good rate capability (a decay of 33% in Csp with charge/discharge rates increasing from 1 to 20 A g(-1)), and high cycle stability (only a small decrease of 4.2% in Csp after 1000 cycles at a scan rate of 100 mV s(-1)). Furthermore, an aqueous symmetric supercapacitor device is fabricated by using the as-prepared composite as electrodes the device demonstrates a high energy density (≈21.2 Wh kg(-1)) and superior long-term cycle ability (only 4.4% and 18.6% loss in Csp after 2000 and 5000 cycles, respectively).
Publisher: Elsevier BV
Date: 10-2009
Publisher: American Chemical Society (ACS)
Date: 11-2005
DOI: 10.1021/CM051735B
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA00129H
Abstract: A new surface P atom-grafted g-C 3 N 4 is developed, and the existence form and function of P atom is presented.
Publisher: American Chemical Society (ACS)
Date: 29-06-2017
Abstract: Dual heteroatom-doped carbon materials are efficient electrocatalysts via a synergistic effect. With nitrogen as the primary dopant, boron, sulfur, and phosphorus can be used as secondary elements for co-doped carbons. However, evaluation and analysis of the promotional effect of B, P, and S to N-doped carbons has not been widely researched. Here we report a robust platform that is constructed through polydopamine to prepare N,B-, N,P-, and N,S-co-doped carbon nanosheets, characterized by similar N species content and efficient B, P, and S doping. Systematic investigation reveals S to have the greatest promotional effect in hydrogen evolution reactions (HER) followed by P and that B decreases the activity of N-doped carbons. Experimental and theoretical analyses show the secondary heteroatom promotional effect is impacted by the intrinsic structures and extrinsic surface areas of both materials, i.e., electronic structures exclusively determine the catalytic activity of active sites, while large surface areas optimize apparent HER performance.
Publisher: Wiley
Date: 12-07-2019
Abstract: Heterogeneous electrocatalysis typically involves charge transfer between surface active sites and adsorbed species. Therefore, modulating the surface charge state of an electrocatalyst can be used to enhance performance. A series of negatively charged transition‐metal (Fe, Co, Ni, Cu,and NiCo) phosphides were fabricated by designing strong electronic coupling with hydr(oxy)oxides formed in situ. Physicochemical characterizations, together with DFT computations, demonstrate that strong electronic coupling renders transition‐metal phosphides negatively charged. This facilitates destabilization of alkaline water adsorption and dissociation to result in significantly improved H 2 evolution. Negatively charged Ni 2 P/nickel hydr(oxy)oxide for ex le exhibits a significantly low overpotential of 138 mV at 100 mA cm −2 , superior to that without strong electronic coupling and also commercial Pt/C.
Publisher: Oxford University Press (OUP)
Date: 23-01-2018
DOI: 10.1093/NSR/NWY010
Publisher: Wiley
Date: 21-03-2016
Abstract: In view of the climate changes caused by the continuously rising levels of atmospheric CO2 , advanced technologies associated with CO2 conversion are highly desirable. In recent decades, electrochemical reduction of CO2 has been extensively studied since it can reduce CO2 to value-added chemicals and fuels. Considering the sluggish reaction kinetics of the CO2 molecule, efficient and robust electrocatalysts are required to promote this conversion reaction. Here, recent progress and opportunities in inorganic heterogeneous electrocatalysts for CO2 reduction are discussed, from the viewpoint of both experimental and computational aspects. Based on elemental composition, the inorganic catalysts presented here are classified into four groups: metals, transition-metal oxides, transition-metal chalcogenides, and carbon-based materials. However, despite encouraging accomplishments made in this area, substantial advances in CO2 electrolysis are still needed to meet the criteria for practical applications. Therefore, in the last part, several promising strategies, including surface engineering, chemical modification, nanostructured catalysts, and composite materials, are proposed to facilitate the future development of CO2 electroreduction.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CE26899C
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4TA01672F
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6CP02119K
Abstract: In this study, we present a detailed understanding on synthesis mechanism of PbS QDs so as to provide guidance for future QDs synthesis.
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR06801H
Abstract: Dual doped carbon sub-microspheres with hierarchical pores synthesized through a soft-template strategy show high performance towards oxygen electrocatalysis.
Publisher: Elsevier BV
Date: 12-2008
Publisher: Wiley
Date: 12-05-2015
Abstract: The development of ordered mesoporous carbon materials with controllable structures and improved physicochemical properties by doping heteroatoms such as nitrogen into the carbon framework has attracted a lot of attention, especially in relation to energy storage and conversion. Herein, a series of nitrogen-doped mesoporous carbon spheres (NMCs) was synthesized via a facile dual soft-templating procedure by tuning the nitrogen content and carbonization temperature. Various physical and (electro)chemical properties of the NMCs have been comprehensively investigated to pave the way for a feasible design of nitrogen-containing porous carbon materials. The optimized s le showed a favorable electrocatalytic activity as evidenced by a high kinetic current and positive onset potential for oxygen reduction reaction (ORR) due to its large surface area, high pore volume, good conductivity, and high nitrogen content, which make it a highly efficient ORR metal-free catalyst in alkaline solutions.
Publisher: Wiley
Date: 21-02-2019
Publisher: American Chemical Society (ACS)
Date: 06-01-2001
DOI: 10.1021/IE000496T
Publisher: IEEE
Date: 2006
Publisher: Research Square Platform LLC
Date: 13-04-2023
DOI: 10.21203/RS.3.RS-2783165/V1
Abstract: Aqueous sodium-ion batteries (ASIBs) are practically promising for large-scale energy storage, but their energy density and lifespan are hindered by water decomposition. Current strategies to enhance the water stability include using expensive fluorine-containing salts to create a solid electrolyte interface or adding potentially-flammable organic co-solvents in the electrolyte to reduce water activity. However, these methods have significantly increased cost and safety risk. Shifting electrolytes from near neutrality to alkalinity can fundamentally suppress hydrogen evolution, but trigger oxygen evolution and cathode dissolution. Here, we present an alkaline-type ASIB with Mn-based Prussian blue analogue cathode, which exhibits a record lifespan of 13,000 cycles at 10 C together with high energy density of 90 Wh kg−1 at 0.5 C. This is achieved by building a nickel/carbon layer to induce a H3O+-rich local environment near the cathode surface, thereby suppressing oxygen evolution and cathode dissolution. Simultaneously, Ni atoms can be in-situ embedded into the cathode to enable its durability. At an industry-level mass loading 30 mg cm−1, the pouch cell exhibits excellent stability with a capacity retention of ~ 100% following 200 cycles at 300 mA g−1, outperforming previously reported aqueous batteries.
Publisher: Elsevier BV
Date: 11-2018
Publisher: Wiley
Date: 09-07-2021
Abstract: Monitoring and controlling the reconstruction of materials under working conditions is crucial for the precise identification of active sites, elucidation of reaction mechanisms, and rational design of advanced catalysts. Herein, a Bi‐based metal–organic framework (Bi‐MOF) for electrochemical CO 2 reduction is selected as a case study. In situ Raman spectra combined with ex situ electron microscopy reveal that the intricate reconstruction of the Bi‐MOF can be controlled using two steps: 1) electrolyte‐mediated dissociation and conversion of Bi‐MOF to Bi 2 O 2 CO 3 , and 2) potential‐mediated reduction of Bi 2 O 2 CO 3 to Bi. The intentionally reconstructed Bi catalyst exhibits excellent activity, selectivity, and durability for formate production, and the unsaturated surface Bi atoms formed during reconstruction become the active sites. This work emphasizes the significant impact of pre‐catalyst reconstruction under working conditions and provides insight into the design of highly active and stable electrocatalysts through the regulation of these processes.
Publisher: Wiley
Date: 22-03-2018
Abstract: The implementation of water splitting systems, powered by sustainable energy resources, appears to be an attractive strategy for producing high-purity H
Publisher: Springer Science and Business Media LLC
Date: 2001
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9NH00361D
Abstract: Atomically dispersed Fe immobilized within N-doped carbon nanosheets was synthesized. The synergistic effect between the metal atom and its anchoring framework sites has been investigated for efficient CO 2 reduction.
Publisher: Wiley
Date: 08-02-2014
Abstract: A three-dimensional (3D) electrode composed of nitrogen, oxygen dualdoped graphene-carbon nanotube hydrogel film is fabricated, which greatly favors the transport and access of gas and reaction intermediates, and shows a remarkable oxygen-evolution catalytic performance in both alkaline and acidic solutions.
Publisher: Springer Science and Business Media LLC
Date: 21-09-2016
DOI: 10.1038/NCOMMS12876
Abstract: Engineering the surface structure at the atomic level can be used to precisely and effectively manipulate the reactivity and durability of catalysts. Here we report tuning of the atomic structure of one-dimensional single-crystal cobalt (II) oxide (CoO) nanorods by creating oxygen vacancies on pyramidal nanofacets. These CoO nanorods exhibit superior catalytic activity and durability towards oxygen reduction/evolution reactions. The combined experimental studies, microscopic and spectroscopic characterization, and density functional theory calculations reveal that the origins of the electrochemical activity of single-crystal CoO nanorods are in the oxygen vacancies that can be readily created on the oxygen-terminated {111} nanofacets, which favourably affect the electronic structure of CoO, assuring a rapid charge transfer and optimal adsorption energies for intermediates of oxygen reduction/evolution reactions. These results show that the surface atomic structure engineering is important for the fabrication of efficient and durable electrocatalysts.
Publisher: Wiley
Date: 13-03-2014
Publisher: Elsevier BV
Date: 05-2020
Publisher: Wiley
Date: 07-2019
Abstract: As photocatalysis technology could transform renewable and clean solar energy into green hydrogen (H
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C5TA09325B
Abstract: Highly dense CdTe nanowire arrays were synthesized in solution by laser-driven absorption and desorption of gold catalysts.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CS00172G
Abstract: The long-standing popularity of semiconductor photocatalysts stimulated their characterization, which is the subject of this review aiming to help materials chemists and physicists, particularly students, to select suitable characterization methods.
Publisher: American Chemical Society (ACS)
Date: 25-03-2021
DOI: 10.1021/JACS.1C01525
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2JM35278H
Publisher: Wiley
Date: 20-09-2023
Abstract: Photogenerated charge localization on material surfaces significantly affects photocatalytic performance, especially for multi‐electron CO 2 reduction. Dual single atom (DSA) catalysts with flexibly designed reactive sites have received significant research attention for CO 2 photoreduction. However, the charge transfer mechanism in DSA catalysts remains poorly understood. Here we report for the first time a reversed electron transfer mechanism on Au and Co DSA catalysts. In situ characterizations confirm that for CdS nanoparticles (NPs) loaded with Co or Au single atoms, photogenerated eletrons are localized around the single atom of Co or Au. In DSA catalysts however electrons are delocalized from Au and accumulate around Co atoms. Importantly, combined advanced spectroscopic findings and theoretical computation evidence that this reversed electron transfer in Au/Co DSA boosts charge redistribution and activation of CO 2 molecules, leading to highly significantly increased photocatalytic CO 2 reduction, for ex le, Au/Co DSA loaded CdS exhibits, respectively, ca . 2800% and 700% greater yields for CO and CH 4 compared with that for CdS alone. Reversed electron transfer in DSA can be used for practical design for charge redistribution and to boost photoreduction of CO 2 . Findings will be of benefit to researchers and manufacturers in DSA loaded catalysts for generation of solar fuels. This article is protected by copyright. All rights reserved
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1CC13658E
Abstract: Yolk/shell or 'rattle-typed' nanomaterials with nanoparticle cores inside hollow shells are interesting among the complex hollow nanostructures. Yolk/shell nanoparticles (YSNs) are promising functional nanomaterials for a variety of applications such as catalysis, delivery, lithium-ion batteries and biosensors due to their tailorability and functionality in both the cores and hollow shells. This feature article provides an overview of advances in this exciting area of YSNs, covering systematic synthesis approaches and key promising applications based on the literature and our own recent work. We present some strategies for the synthesis of YSNs with controllable sizes, compositions, geometries, structures and functionalities. Applications of these new materials in a wide range of potential areas are discussed including nanoreactors, biomedicine and lithium-ion batteries. Promising future directions of this active research field are also highlighted.
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1JM12054A
Publisher: Wiley
Date: 22-01-2013
Publisher: Elsevier BV
Date: 30-05-2009
DOI: 10.1016/J.JHAZMAT.2008.09.023
Abstract: Hybrid materials of silicalite-1 (Sil-1)-coated SBA-15 particles (MSs) have been successfully synthesized by crystallization process under hydrothermal conditions. These MSs materials were characterized by X-ray diffraction, nitrogen adsorption/desorption and TEM techniques, which illustrated that the silicalite-1-coated SBA-15 particles were successfully prepared and had large pore volume and hierarchical pore size distribution. Further experimental studies indicated that longer crystallization time under basic condition caused the mesostructure of SBA-15 materials to collapse destructively and higher calcination temperature tended to disrupt the long-range mesoscopic order while they had little influence on the phase of microcrystalline silicalite-1 zeolite. The resultant MSs materials were investigated by estimating dynamic adsorption capacity under dry and wet conditions to evaluate their adsorptive and hydrophobic properties. The hydrophobicity index (HI) value followed the sequence of silicalite-1>MSs>SBA-15, which revealed that the SBA-15 particles coated with the silicalite-1 seeds enhanced the surface hydrophobicity, and also were consistent with FTIR results. Our studies show that MSs materials combined the advantages of the ordered mesoporous material (high adsorptive capacity, large pore volume) and silicalite-1 zeolite (super-hydrophobic property, high hydrothermal stability), and the presence of micropores directly led to an increase in the dynamic adsorption capacity of benzene under dry and wet conditions.
Publisher: Wiley
Date: 21-10-2021
Abstract: Aqueous Zn‐ion batteries (ZIBs) are regarded as alternatives to Li‐ion batteries benefiting from both improved safety and environmental impact. The widespread application of ZIBs, however, is compromised by the lack of high‐performance cathodes. Currently, only the intercalation mechanism is widely reported in aqueous ZIBs, which significantly limits cathode options. Beyond Zn‐ion intercalation, we comprehensively study the conversion mechanism for Zn 2+ storage and its diffusion pathway in a CuI cathode, indicating that CuI occurs a direct conversion reaction without Zn 2+ intercalation due to the high energy barrier for Zn 2+ intercalation and migration. Importantly, this direct conversion reaction mechanism can be readily generalized to other high‐capacity cathodes, such as Cu 2 S (336.7 mA h g −1 ) and Cu 2 O (374.5 mA h g −1 ), indicating its practical universality. Our work enriches the Zn‐ion storage mechanism and significantly broadens the cathode horizons towards next‐generation ZIBs.
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR04666A
Abstract: Cost-effective electrocatalysts for oxygen evolution reaction are attractive for energy conversion processes.
Publisher: Elsevier BV
Date: 09-2010
Publisher: Springer Science and Business Media LLC
Date: 26-03-2019
Publisher: Elsevier BV
Date: 02-2009
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9CS00280D
Abstract: A guidebook with best practices and potential opportunities to explore ambient electrocatalytic nitrogen reduction reliably and insightfully.
Publisher: American Chemical Society (ACS)
Date: 06-12-2016
DOI: 10.1021/JACS.6B11291
Abstract: Hydrogen evolution reaction (HER) is a critical process due to its fundamental role in electrocatalysis. Practically, the development of high-performance electrocatalysts for HER in alkaline media is of great importance for the conversion of renewable energy to hydrogen fuel via photoelectrochemical water splitting. However, both mechanistic exploration and materials development for HER under alkaline conditions are very limited. Precious Pt metal, which still serves as the state-of-the-art catalyst for HER, is unable to guarantee a sustainable hydrogen supply. Here we report an anomalously structured Ru catalyst that shows 2.5 times higher hydrogen generation rate than Pt and is among the most active HER electrocatalysts yet reported in alkaline solutions. The identification of new face-centered cubic crystallographic structure of Ru nanoparticles was investigated by high-resolution transmission electron microscopy imaging, and its formation mechanism was revealed by spectroscopic characterization and theoretical analysis. For the first time, it is found that the Ru nanocatalyst showed a pronounced effect of the crystal structure on the electrocatalytic activity tested under different conditions. The combination of electrochemical reaction rate measurements and density functional theory computation shows that the high activity of anomalous Ru catalyst in alkaline solution originates from its suitable adsorption energies to some key reaction intermediates and reaction kinetics in the HER process.
Publisher: Springer Science and Business Media LLC
Date: 18-05-2023
DOI: 10.1038/S41467-023-38497-3
Abstract: Acidic CO 2 -to-HCOOH electrolysis represents a sustainable route for value-added CO 2 transformations. However, competing hydrogen evolution reaction (HER) in acid remains a great challenge for selective CO 2 -to-HCOOH production, especially in industrial-level current densities. Main group metal sulfides derived S-doped metals have demonstrated enhanced CO 2 -to-HCOOH selectivity in alkaline and neutral media by suppressing HER and tuning CO 2 reduction intermediates. Yet stabilizing these derived sulfur dopants on metal surfaces at large reductive potentials for industrial-level HCOOH production is still challenging in acidic medium. Herein, we report a phase-engineered tin sulfide pre-catalyst (π-SnS) with uniform rhombic dodecahedron structure that can derive metallic Sn catalyst with stabilized sulfur dopants for selective acidic CO 2 -to-HCOOH electrolysis at industrial-level current densities. In situ characterizations and theoretical calculations reveal the π-SnS has stronger intrinsic Sn-S binding strength than the conventional phase, facilitating the stabilization of residual sulfur species in the Sn subsurface. These dopants effectively modulate the CO 2 RR intermediates coverage in acidic medium by enhancing *OCHO intermediate adsorption and weakening *H binding. As a result, the derived catalyst (Sn(S)-H) demonstrates significantly high Faradaic efficiency (92.15 %) and carbon efficiency (36.43 %) to HCOOH at industrial current densities (up to −1 A cm −2 ) in acidic medium.
Publisher: Elsevier BV
Date: 04-2003
Publisher: Wiley
Date: 27-02-2019
Abstract: The establishment of electrocatalysts with bifunctionality for efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic environments is necessary for the development of proton exchange membrane (PEM) water electrolyzers for the production of clean hydrogen fuel. RuIr alloy is considered to be a promising electrocatalyst because of its favorable OER performance and potential for HER. Here, the design of a bifunctional electrocatalyst with greatly boosted water‐splitting performance from doping RuIr alloy nanocrystals with transition metals that modify electronic structure and binding strength of reaction intermediates is reported. Significantly, Co‐RuIr results in small overpotentials of 235 mV for OER and 14 mV for HER (@ 10 mA cm −2 current density) in 0.1 m HClO 4 media. Therefore a cell voltage of just 1.52 V is needed for overall water splitting to produce hydrogen and oxygen. More importantly, for a series of M‐RuIr (M = Co, Ni, Fe), the catalytic activity dependence at fundamental level on the chemical/valence states is used to establish a novel composition‐activity relationship. This permits new design principles for bifunctional electrocatalysts.
Publisher: Wiley
Date: 21-09-2020
Publisher: Elsevier BV
Date: 05-2000
Publisher: Wiley
Date: 24-02-2021
Publisher: Wiley
Date: 25-08-2014
Abstract: Three-dimensional hierarchical porous graphene/carbon composite was successfully synthesized from a solution of graphene oxide and a phenolic resin by using a facile and efficient method. The morphology, structure, and surface property of the composite were investigated intensively by a variety of means such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). It is found that graphene serves as a scaffold to form a hierarchical pore texture in the composite, resulting in its superhigh surface area of 2034 m(2) g(-1), thin macropore wall, and high conductivity (152 S m(-1)). As evidenced by electrochemical measurements in both EMImBF4 ionic liquid and KOH electrolyte, the composite exhibits ideal capacitive behavior, high capacitance, and excellent rate performance due to its unique structure. In EMImBF4 , the composite has a high energy density of up to 50.1 Wh kg(-1) and also possesses quite stable cycling stability at 100 °C, suggesting its promising application in high-temperature supercapacitors. In KOH electrolyte, the specific capacitance of this composite can reach up to an unprecedented value of 186.5 F g(-1), even at a very high current density of 50 A g(-1), suggesting its prosperous application in high-power applications.
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3TA00133D
Publisher: Wiley
Date: 31-12-2021
Publisher: Wiley
Date: 02-05-2019
Abstract: Zinc-based electrochemistry is attracting significant attention for practical energy storage owing to its uniqueness in terms of low cost and high safety. However, the grid-scale application is plagued by limited output voltage and inadequate energy density when compared with more conventional Li-ion batteries. Herein, we propose a latent high-voltage MnO
Publisher: American Chemical Society (ACS)
Date: 12-08-2012
DOI: 10.1021/NN2039643
Abstract: Large pore mesoporous silica nanoparticles (LP-MSNs) functionalized with poly-L-lysine (PLL) were designed as a new carrier material for gene delivery applications. The synthesized LP-MSNs are 100-200 nm in diameter and are composed of cage-like pores organized in a cubic mesostructure. The size of the cavities is about 28 nm with an entrance size of 13.4 nm. Successful grafting of PLL onto the silica surface through covalent immobilization was confirmed by X-ray photoelectron spectroscopy, solid-state (13)C magic-angle spinning nuclear magnetic resonance, Fourier transformed infrared, and thermogravimetric analysis. As a result of the particle modification with PLL, a significant increase of the nanoparticle binding capacity for oligo-DNAs was observed compared to the native unmodified silica particles. Consequently, PLL-functionalized nanoparticles exhibited a strong ability to deliver oligo DNA-Cy3 (a model for siRNA) to Hela cells. Furthermore, PLL-functionalized nanoparticles were proven to be superior as gene carriers compared to amino-functionalized nanoparticles and the native nanoparticles. The system was tested to deliver functional siRNA against minibrain-related kinase and polo-like kinase 1 in osteosarcoma cancer cells. Here, the functionalized particles demonstrated great potential for efficient gene transfer into cancer cells as a decrease of the cellular viability of the osteosarcoma cancer cells was induced. Moreover, the PLL-modified silica nanoparticles also exhibit a high biocompatibility, with low cytotoxicity observed up to 100 μg/mL.
Publisher: Wiley
Date: 26-10-2016
Abstract: A potassium iron (II) hexacyanoferrate nanocube cathode material is reported, which operates with an aqueous electrolyte to deliver exceptionally high capacities (up to 120 mA h g
Publisher: Elsevier BV
Date: 12-2021
Publisher: Wiley
Date: 08-02-2018
Publisher: Wiley
Date: 07-07-2019
Publisher: American Chemical Society (ACS)
Date: 29-11-2018
Abstract: Transition metal nitrides (TMNs) have great potential for energy-related electrocatalysis because of their inherent electronic properties. However, incorporating nitrogen into a transition metal lattice is thermodynamically unfavorable, and therefore most of the developed TMNs are deficient in nitrogen. Consequently, these TMNs exhibit poor structural stability and unsatisfactory performance for electrocatalytic applications. In this work, we design and synthesize an atomically thin nitrogen-rich nanosheets, Mo
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5EE02650D
Abstract: Porous P-doped g-C 3 N 4 nanosheets prepared by combining P doping and thermal exfoliation exhibit a high visible-light photocatalytic H 2 -production activity of 1596 μmol h −1 g −1 and a quantum efficiency of 3.56% at 420 nm.
Publisher: Wiley
Date: 14-05-2018
Abstract: The hydrogen evolution reaction (HER) is a fundamental process in electrocatalysis and plays an important role in energy conversion for the development of hydrogen-based energy sources. However, the considerably slow rate of the HER in alkaline conditions has hindered advances in water splitting techniques for high-purity hydrogen production. Differing from well documented acidic HER, the mechanistic aspects of alkaline HER are yet to be settled. A critical appraisal of alkaline HER electrocatalysis is presented, with a special emphasis on the connection between fundamental surface electrochemistry on single-crystal models and the derived molecular design principle for real-world electrocatalysts. By presenting some typical ex les across theoretical calculations, surface characterization, and electrochemical experiments, we try to address some key ongoing debates to deliver a better understanding of alkaline HER at the atomic level.
Publisher: Elsevier
Date: 2007
Publisher: Wiley
Date: 04-10-2021
Abstract: The physicochemical properties of metal‐organic frameworks (MOFs) significantly depend on composition, topology, and porosity, which can be tuned via synthesis. In addition to a classic direct synthesis, postsynthesis modulations of MOFs, including ion exchange, installation, and destruction, can significantly expand the application. Because of a limitation of the qualitative hard and soft acids and bases (HSAB) theory, posttreatment permits regulation of MOF structure by cleaving chemical bonds at the molecular level. Here, methods of coordination bond scission to tailor the structure are critically appraised and the application to energy storage and conversion is assessed. MOF structures synthesized by molecular‐level coordination bond cleavage are described and the corresponding MOFs for electrocatalysis and renewable battery applications are evaluated. Significant emphasis is placed on various coordination bond cleavage to tune properties, including chemical groups, electronic structures, and morphologies. The review concludes with a critical perspective on practical application, together with challenges and future outlook for this emerging field.
Publisher: Wiley
Date: 10-06-2015
Publisher: Wiley
Date: 08-04-2019
Publisher: Elsevier BV
Date: 2021
Publisher: Wiley
Date: 21-05-2012
Publisher: Wiley
Date: 27-09-2023
Publisher: Wiley
Date: 19-05-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0JM04412A
Publisher: American Chemical Society (ACS)
Date: 16-02-2023
Publisher: Wiley
Date: 10-2015
Abstract: Mesoporous silica nanoparticles are modified with dual targeting ligands, i.e., folic acid and dexamethasone, to construct a cancer-cell-specific nuclear-targeted delivery system. The resulting nanocarriers can not only enhance the inhibition efficacy of doxorubicin on Hela cells through active nucleus accumulation but also reduce toxic side effects on noncancer cells though receptor-mediated selective cellular uptake.
Publisher: Wiley
Date: 16-03-2023
Abstract: Zn electrodes in aqueous media exhibit an unstable Zn/electrolyte interface due to severe parasitic reactions and dendrite formation. Here, a dynamic Zn interface modulation based on the molecular switch strategy is reported by hiring γ‐butyrolactone (GBL) in ZnCl 2 /H 2 O electrolyte. During Zn plating, the increased interfacial alkalinity triggers molecular switch from GBL to γ‐hydroxybutyrate (GHB). GHB strongly anchors on Zn surface via triple Zn−O bonding, leading to suppressive hydrogen evolution and texture‐regulated Zn morphology. Upon Zn stripping, the fluctuant pH turns the molecular switch reaction off through the cyclization of GHB to GBL. This dynamic molecular switch strategy enables high Zn reversibility with Coulombic efficiency of 99.8 % and Zn||iodine batteries with high‐cyclability under high Zn depth of discharge (50 %). This study demonstrates the importance of dynamic modulation for Zn electrode and realizes the reversible molecular switch strategy to enhance its reversibility.
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D0TA11604A
Abstract: Understanding the late stages of C 2 pathways provides great opportunities for fully achieving a selective CO 2 electroreduction. The C 2 product selectivity can be directed by the active site's oxygen affinity on a range of non-metal doped Cu surfaces.
Publisher: Wiley
Date: 02-05-2022
Abstract: Aqueous Zn–iodine (Zn–I 2 ) batteries have been regarded as a promising energy‐storage system owing to their high energy ower density, safety, and cost‐effectiveness. However, the polyiodide shuttling results in serious active mass loss and Zn corrosion, which limits the cycling life of Zn–I 2 batteries. Inspired by the chromogenic reaction between starch and iodine, a structure confinement strategy is proposed to suppress polyiodide shuttling in Zn–I 2 batteries by hiring starch, due to its unique double‐helix structure. In situ Raman spectroscopy demonstrates an I 5 − ‐dominated I − /I 2 conversion mechanism when using starch. The I 5 − presents a much stronger bonding with starch than I 3 − , inhibiting the polyiodide shuttling in Zn–I 2 batteries, which is confirmed by in situ ultraviolet–visible spectra. Consequently, a highly reversible Zn–I 2 battery with high Coulombic efficiency (≈100% at 0.2 A g −1 ) and ultralong cycling stability ( 000 cycles) is realized. Simultaneously, the Zn corrosion triggered by polyiodide is effectively inhibited owing to the desirable shuttling‐suppression by the starch, as evidenced by X‐ray photoelectron spectroscopy analysis. This work provides a new understanding of the failure mechanism of Zn–I 2 batteries and proposes a cheap but effective strategy to realize high‐cyclability Zn–I 2 batteries.
Publisher: American Chemical Society (ACS)
Date: 05-03-2005
DOI: 10.1021/IE048931X
No related grants have been discovered for Shi Zhang Qiao.