ORCID Profile
0000-0002-3285-9982
Current Organisation
UNSW Sydney
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Publisher: Elsevier BV
Date: 06-2022
Publisher: Wiley
Date: 08-01-2019
Abstract: Nickel-heteroatoms bridge sites are important reaction descriptors for many catalytic and electrochemical processes. Herein we report the controllable surface modification of nickel-nitrogen (Ni-N) bridge sites on metallic Ni particles via a simplified vapor-assisted treatment approach. X-ray absorption spectroscopy (XAS) and Operando Raman spectroscopy verifies the interaction between Ni and surface-anchored N, which leads to distorted Ni lattice structure with improved wettability. The Ni-N bridge sites with appropriate N coverage level plays a critical role in the enhanced hydrogen evolution reaction (HER) and the optimized electrode (Ni-N
Publisher: Wiley
Date: 17-09-2020
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.ULTRAMIC.2021.113420
Abstract: Revealing the position of materials with chemical selectivity at atomic scale within functional nanoparticles is essential to understand and control their performance and cutting-edge atom probe tomography is a powerful tool to undertake this task. In this paper, we demonstrate three effective methods to prepare the needle-shaped specimens required for atom probe tomography measurements from nanoparticles of different sizes and provide ex les of how atom probe can be used to provide data that is critical to their functionality. S les measured include lithium-ion batteries (LIBs) cathode nanoparticles (300 - 500 nm), nickel-doped silicon dioxide (Ni@SiO
Publisher: Pensoft Publishers
Date: 21-06-2023
DOI: 10.3897/ARPHAPREPRINTS.E108104
Abstract: Ecosystem Accounting provides a framework to measure and value relationships between ecosystems, society and the economy. The accounts measure ecosystem extent, condition, and services, providing the means to identify and internalise ecological degradation, as well as understanding the risks and dependencies of economic activities on the environment and tracking progress towards sustainable development. The OSPAR Convention, which concerns the protection of the Marine Environment for the North-East Atlantic, has committed to accounting for natural capital and ecosystem services, where the UN System of Environmental Economic Accounting – Ecosystem Accounting (SEEA EA) provides an international accounting standard for guidance in compiling accounts. Here, we describe the first attempt in compiling accounts aligned with SEEA EA at a Regional Sea scale. We (i) identified existing open access data, (ii) produced accounts for selected ecosystems and valued their services and asset value, and (iii) identified challenges and lessons learned. For ecosystem services, we measured fish provisioning, carbon sequestration, and outdoor recreation from coastal and marine environments across OSPAR contracting parties. The exercise identified lack of fitting data at regional level, spatially explicit linkages and harmonisation need to be overcome to further expand accounts. This work represents an initial step to progress on ecosystem accounting and demonstrates that even with limited data and incomplete timeseries, accounts can start compiling to identify data gaps, and prioritize next steps.
Publisher: Elsevier BV
Date: 09-2021
Publisher: American Chemical Society (ACS)
Date: 10-01-2022
Publisher: Elsevier BV
Date: 12-2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0EE00666A
Abstract: A PH 3 vapor-assisted phase and structure engineering strategy to convert non-active NiTe into super-active Ni 2 P/NiTe 2 catalysts for hydrogen evolution reaction.
Publisher: Routledge
Date: 11-10-2021
Publisher: Elsevier BV
Date: 12-2020
Publisher: American Chemical Society (ACS)
Date: 06-07-2021
DOI: 10.1021/ACS.CHEMREV.0C01328
Abstract: Global energy and environmental crises are among the most pressing challenges facing humankind. To overcome these challenges, recent years have seen an upsurge of interest in the development and production of renewable chemical fuels as alternatives to the nonrenewable and high-polluting fossil fuels. Photocatalysis, photoelectrocatalysis, and electrocatalysis provide promising avenues for sustainable energy conversion. Single- and dual-component catalytic systems based on nanomaterials have been intensively studied for decades, but their intrinsic weaknesses h er their practical applications. Multicomponent nanomaterial-based systems, consisting of three or more components with at least one component in the nanoscale, have recently emerged. The multiple components are integrated together to create synergistic effects and hence overcome the limitation for outperformance. Such higher-efficiency systems based on nanomaterials will potentially bring an additional benefit in balance-of-system costs if they exclude the use of noble metals, considering the expense and sustainability. It is therefore timely to review the research in this field, providing guidance in the development of noble-metal-free multicomponent nanointegration for sustainable energy conversion. In this work, we first recall the fundamentals of catalysis by nanomaterials, multicomponent nanointegration, and reactor configuration for water splitting, CO
Publisher: Wiley
Date: 15-09-2021
Abstract: Transition metal nitrogen carbon based single‐atom catalysts (SACs) have exhibited superior activity and selectivity for CO 2 electroreduction to CO. A favorable local nitrogen coordination environment is key to construct efficient metal‐N moieties. Here, a facile plasma‐assisted and nitrogen vacancy (NV) induced coordinative reconstruction strategy is reported for this purpose. Under continuous plasma striking, the preformed pentagon pyrrolic N‐defects around Ni sites can be transformed to a stable pyridinic N dominant Ni‐N 2 coordination structure with promoted kinetics toward the CO 2 ‐to‐CO conversion. Both the CO selectivity and productivity increase markedly after the reconstruction, reaching a high CO Faradaic efficiency of 96% at mild overpotential of 590 mV and a large CO current density of 33 mA cm ‐2 at 890 mV. X‐ray adsorption spectroscopy and density functional theory (DFT) calculations reveal this defective local N environment decreases the restraint on central Ni atoms and provides enough space to facilitate the adsorption and activation of CO 2 molecule, leading to a reduced energy barrier for CO 2 reduction.
Publisher: American Chemical Society (ACS)
Date: 24-10-2018
Publisher: Royal Society of Chemistry (RSC)
Date: 2023
DOI: 10.1039/D3EY00182B
Abstract: A single frequency impedance method is introduced, based on an optimum high frequency of minimum phase and faradaic processes, to monitor gas bubble evolution during water electrolysis in operando .
Publisher: Springer Science and Business Media LLC
Date: 04-03-2021
DOI: 10.1038/S41467-021-21750-Y
Abstract: Direct experimental observations of the interface structure can provide vital insights into heterogeneous catalysis. Ex les of interface design based on single atom and surface science are, however, extremely rare. Here, we report Cu–Sn single-atom surface alloys, where isolated Sn sites with high surface densities (up to 8%) are anchored on the Cu host, for efficient electrocatalytic CO 2 reduction. The unique geometric and electronic structure of the Cu–Sn surface alloys (Cu 97 Sn 3 and Cu 99 Sn 1 ) enables distinct catalytic selectivity from pure Cu 100 and Cu 70 Sn 30 bulk alloy. The Cu 97 Sn 3 catalyst achieves a CO Faradaic efficiency of 98% at a tiny overpotential of 30 mV in an alkaline flow cell, where a high CO current density of 100 mA cm −2 is obtained at an overpotential of 340 mV. Density functional theory simulation reveals that it is not only the elemental composition that dictates the electrocatalytic reactivity of Cu–Sn alloys the local coordination environment of atomically dispersed, isolated Cu–Sn bonding plays the most critical role.
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D1EE02013G
Abstract: Direct synthesis of Ni 3 N/Ni catalyst enriched with N-vacancies using one-step reactive magnetron sputtering with enhanced performance for the hydrogen evolution reaction in photoelectrochemical cells and electrolysers.
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0EE01609H
Abstract: The catalytic active sites of NiFe and NiFeCr (oxy)hydroxides are revealed by operando spectroscopic techonologies for alkaline water oxidation.
Publisher: Wiley
Date: 24-07-2021
Abstract: While direct solar‐driven water splitting has been investigated as an important technology for low‐cost hydrogen production, the systems demonstrated so far either required expensive materials or presented low solar‐to‐hydrogen (STH) conversion efficiencies, both of which increase the levelized cost of hydrogen (LCOH). Here, a low‐cost material system is demonstrated, consisting of perovskite/Si tandem semiconductors and Ni‐based earth‐abundant catalysts for direct solar hydrogen generation. NiMo‐based hydrogen evolution reaction catalyst is reported, which has innovative “flower‐stem” morphology with enhanced reaction sites and presents very low reaction overpotential of 6 mV at 10 mA cm −2 . A perovskite solar cell with an unprecedented high open circuit voltage ( V oc ) of 1.271 V is developed, which is enabled by an optimized perovskite composition and an improved surface passivation. When the NiMo hydrogen evolution catalyst is wire‐connected with an optimally designed NiFe‐based oxygen evolution catalyst and a high‐performance perovskite‐Si tandem cell, the resulting integrated water splitting cell achieves a record 20% STH efficiency. Detailed analysis of the integrated system reveals that STH efficiencies of 25% can be achieved with realistic improvements in the perovskite cell and an LCOH below ≈ $3 kg −1 is feasible.
Publisher: Pensoft Publishers
Date: 10-07-2023
Abstract: Ecosystem Accounting provides a framework to measure and value relationships amongst ecosystems, society and the economy. The accounts measure ecosystem extent, condition and services, providing the means to identify and internalise ecological degradation, as well as understanding the risks and dependencies of economic activities on the environment and tracking progress towards sustainable development. The OSPAR Convention, which concerns the protection of the Marine Environment for the North-East Atlantic, has committed to accounting for natural capital and ecosystem services, where the UN System of Environmental Economic Accounting – Ecosystem Accounting (SEEA EA) provides an international accounting standard for guidance in compiling accounts. Here, we describe the first attempt in compiling accounts aligned with SEEA EA at a Regional Sea scale. We: (i) identified existing open access data, (ii) produced accounts for selected ecosystems and valued their services and asset value and (iii) identified challenges and lessons learned. For ecosystem services, we measured fish provisioning, carbon sequestration and outdoor recreation from coastal and marine environments across OSPAR contracting parties. The exercise identified lack of fitting data at regional level, spatially-explicit linkages and harmonisation need to be overcome to further expand accounts. This work represents an initial step to progress on ecosystem accounting and demonstrates that even with limited data and incomplete time-series, accounts can start being compiled to identify data gaps and prioritising next steps.
Publisher: Springer Science and Business Media LLC
Date: 02-2023
DOI: 10.1038/S41467-023-36100-3
Abstract: Electrocatalytic synergy is a functional yet underrated concept in electrocatalysis. Often, it materializes as intermetallic interaction between different metals. We demonstrate interphasic synergy in monometallic structures is as much effective. An interphasic synergy between Ni(OH) 2 and Ni-N/Ni-C phases is reported for alkaline hydrogen evolution reaction that lowers the energy barriers for hydrogen adsorption-desorption and facilitates that of hydroxyl intermediates. This makes ready-to-serve Ni active sites and allocates a large amount of Ni d -states at Fermi level to promote charge redistribution from Ni(OH) 2 to Ni-N/Ni-C and the co-adsorption of H ads and OH ads intermediates on Ni-N/Ni-C moieties. As a result, a Ni(OH) 2 @Ni-N/Ni-C hetero-hierarchical nanostructure is developed, lowering the overpotentials to deliver −10 and −100 mA cm −2 in alkaline media by 102 and 113 mV, respectively, compared to monophasic Ni(OH) 2 catalyst. This study unveils the interphasic synergy as an effective strategy to design monometallic electrocatalysts for water splitting and other energy applications.
Publisher: Springer Science and Business Media LLC
Date: 06-2020
DOI: 10.1038/S41467-020-16554-5
Abstract: Nickel-based catalysts are most commonly used in industrial alkaline water electrolysis. However, it remains a great challenge to address the sluggish reaction kinetics and severe deactivation problems of hydrogen evolution reaction (HER). Here, we show a Cu-doped Ni catalyst implanted with Ni-O-VOx sites (Ni(Cu)VOx) for alkaline HER. The optimal Ni(Cu)VOx electrode exhibits a near-zero onset overpotential and low overpotential of 21 mV to deliver –10 mA cm −2 , which is comparable to benchmark Pt/C catalyst. Evidence for the formation of Ni-O-VOx sites in Ni(Cu)VOx is established by systematic X-ray absorption spectroscopy studies. The VOx can cause a substantial d ening of Ni lattice and create an enlarged electrochemically active surface area. First-principles calculations support that the Ni-O-VOx sites are superactive and can promote the charge redistribution from Ni to VOx, which greatly weakens the H-adsorption and H 2 release free energy over Ni. This endows the Ni(Cu)VOx electrode high HER activity and long-term durability.
Publisher: Coastal Education and Research Foundation
Date: 07-2017
Publisher: American Chemical Society (ACS)
Date: 12-04-2023
Publisher: American Chemical Society (ACS)
Date: 08-03-2016
Abstract: Ambient fine particulate matter (PM) affects both human health and climate. To reduce the PM2.5 (mass of particles below 2.5 μm in diameter) concentration of an in idual's living environment, ionic liquid-modified polyacrylonitrile (PAN) nanofibers with superior PM2.5 capture capacity were prepared by electrospinning. Ionic liquid diethylammonium dihydrogen phosphate (DEAP) with high viscosity and hydrophilicity was involved during the electrospinning process. Observations by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and water contact angle measurement suggested that the modification of DEAP on PAN effectively altered the morphology (roughness) and surface properties (hydrophilicity) of the PAN nanofibers. The PM2.5 capture measurement was performed in a closed and static system, which mimicked the static hazy weather without wind flow. As a result, DEAP-modified PAN nanofibers exhibited significantly enhanced PM2.5 capture capacity compared to that of the bare PAN nanofibers. This can be attributed to the improved surface roughness (i.e., improved adsorption sites), hydrophilicity, and dipole moment of PAN upon DEAP modification.
Publisher: American Chemical Society (ACS)
Date: 26-05-2009
DOI: 10.1021/JA8092295
Abstract: Unexpected nonadditivity of currents encountered in the electrochemistry of mixtures of ferrocene (Fc) and cobaltocenium cation (Cc(+)) as the PF(6)(-) salt has been investigated by direct current (dc) and Fourier-transformed alternating current (ac) cyclic voltammetry in two aprotic (1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate) and three protic (triethylammonium formate, bis(2-hydroxyethyl)ammonium acetate, and triethylammonium acetate) ionic liquids (ILs). The voltammetry of the in idual Fc(0/+) and Cc(+/0) couples always exhibits near-Nernstian behavior at glassy carbon and gold electrodes. As expected for an ideal process, the reversible formal potentials and diffusion coefficients at 23 +/- 1 degrees C in each IL determined from measurement on in idual Fc and Cc(+) solutions were found to be independent of electrode material, concentration, and technique used for the measurement. However, when Fc and Cc(+) were simultaneously present, the dc and ac peak currents per unit concentration for the Fc(0/+) and Cc(+/0) processes were found to be significantly enhanced in both aprotic and protic ILs. Thus, the apparent diffusion coefficient values calculated for Fc and Cc(+) were respectively found to be about 25 and 35% larger than those determined in idually in the aprotic ILs. A similar change in the Fc(0/+) mass transport characteristics was observed upon addition of tetrabutylammonium hexafluorophosphate (Bu(4)NPF(6)), and the double layer capacitance also varied in distinctly different ways when Fc and Cc(+) were present in idually or in mixtures. Importantly, the nonadditivity of Faradaic current is not associated with a change in viscosity or from electron exchange as found when some solutes are added to ILs. The observation that the (1)H NMR T(1) relaxation times for the proton resonance in Cc(+) also are modified in mixed systems implies that specific interaction with aggregates of the constituent IL ionic species giving rise to subtle structural changes plays an important role in modifying the mass transport, double layer characteristics, and dynamics when solutes of interest in this study are added to ILs. Analogous voltammetric changes were not observed in studies in organic solvent media containing 0.1 M added supporting electrolyte. Implications of the nonadditivity of Faradaic and capacitance terms in ILs are considered.
Publisher: Pensoft Publishers
Date: 12-07-2022
Abstract: Coasts lie at the interface between terrestrial and marine environments, where complex interrelationships and feedbacks between environmental, social and economic factors provide a challenge for decision-making. The knowledge and data needed to link and measure these multiple domains are often highly fragmented and incoherent. Ocean Accounting provides a means to organise relevant ocean data into a common framework, grounded in existing international statistical standards for national and environmental-economic accounting. Here, we test Ocean Accounting within Lake Illawarra, New South Wales (Australia), compiling accounts for the years between 2010 and 2020, inclusive, to measure the extent of coastal vegetation (mangrove, tidal marsh and seagrass) and associated ecosystem services flows (climate change mitigation, eutrophication mitigation) in physical and monetary terms and associated production and employment within sectors of the ocean economy. The accounts show an increase in mangroves by 2 ha and a decrease in seagrass of 80 ha. A net increase was observed in the amount of carbon, nitrogen and phosphorus sequestered across coastal vegetation, due to the expansion of mangroves. Alongside changes in ecosystem extent, a 2-fold increase in full-time ocean-related employment was observed. Fisheries catch also showed significant variation over the 10-year period, where dependencies were observed between commercial species with seagrass and tidal marsh. The relationships and measures derived from accounts provide a cohesive and integrated understanding to provide information for the management and standardised ecosystem service assessments.
Publisher: African Journals Online (AJOL)
Date: 29-11-2022
DOI: 10.4314/WIOJMS.SI2022.1.11
Abstract: The Western Indian Ocean (WIO) is critical in supporting the social and economic development of the nations it borders. To safeguard the various opportunities it provides, it is essential to adopt sustainable ocean development models that balance ocean wealth and ocean health. Such models depend on evidence-based and adaptative ocean governance underpinned by holistic social, environmental and economic indicators. The ocean accounts framework provides a standard accounting structure to integrate social, economic and environmental information in alignment with relevant international statistical standards such as the System of National Accounts and the System of Environmental-Economic Accounting. Applying such a framework produces integrated indicators against which changes can be assessed and measured. These indicators also inform decision-making and support the prioritisation of areas requiring further attention by highlighting data deficiencies, ocean governance gaps and under-explored research areas. The framework encompasses and links several systems of accounting that can be used based on specific priorities. However, three initiation points have been identified that can be further expanded and concatenated into other accounts encompassed by the framework. This publication provides practical guidelines to start implementing national, regional or local ocean accounts, following the Global Ocean Accounts Partnership Technical Guidance on Ocean Accounting. It is further complemented by amendments proposed by the African Community of Practice based on lessons learned during the implementation of ocean accounts pilots across the WIO region. Compiling ocean accounts is an adaptative and iterative process and should be constantly ameliorated and adjusted to local contexts and priorities. However, efforts should be made to maintain coherence with the framework and international standards.
Publisher: Wiley
Date: 15-07-2018
Abstract: Achieving stability with highly active Ru nanoparticles for electrocatalysis is a major challenge for the oxygen evolution reaction. As improved stability of Ru catalysts has been shown for bulk surfaces with low-index facets, there is an opportunity to incorporate these stable facets into Ru nanoparticles. Now, a new solution synthesis is presented in which hexagonal close-packed structured Ru is grown on Au to form nanoparticles with 3D branches. Exposing low-index facets on these 3D branches creates stable reaction kinetics to achieve high activity and the highest stability observed for Ru nanoparticle oxygen evolution reaction catalysts. These design principles provide a synthetic strategy to achieve stable and active electrocatalysts.
Publisher: Springer Science and Business Media LLC
Date: 07-09-2022
Publisher: Informa UK Limited
Date: 17-02-2021
Publisher: Springer Science and Business Media LLC
Date: 06-12-2019
DOI: 10.1038/S41467-019-13415-8
Abstract: Efficient generation of hydrogen from water-splitting is an underpinning chemistry to realize the hydrogen economy. Low cost, transition metals such as nickel and iron-based oxides/hydroxides have been regarded as promising catalysts for the oxygen evolution reaction in alkaline media with overpotentials as low as ~200 mV to achieve 10 mA cm −2 , however, they are generally unsuitable for the hydrogen evolution reaction. Herein, we show a Janus nanoparticle catalyst with a nickel–iron oxide interface and multi-site functionality for a highly efficient hydrogen evolution reaction with a comparable performance to the benchmark platinum on carbon catalyst. Density functional theory calculations reveal that the hydrogen evolution reaction catalytic activity of the nanoparticle is induced by the strong electronic coupling effect between the iron oxide and the nickel at the interface. Remarkably, the catalyst also exhibits extraordinary oxygen evolution reaction activity, enabling an active and stable bi-functional catalyst for whole cell water-splitting with, to the best of our knowledge, the highest energy efficiency (83.7%) reported to date.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Ubiquity Press, Ltd.
Date: 2023
DOI: 10.5334/CSTP.563
Publisher: Wiley
Date: 17-09-2020
Publisher: Wiley
Date: 17-04-2021
Abstract: Nickel‐based electrocatalysts are promising candidates for oxygen evolution reaction (OER) but suffer from high activation overpotentials. Herein, in situ structural reconstruction of V‐doped Ni 2 P pre‐catalyst to form highly active NiV oxyhydroxides for OER is reported, during which the partial dissolution of V creates a disordered Ni structure with an enlarged electrochemical surface area. Operando electrochemical impedance spectroscopy reveals that the synergistic interaction between the Ni hosts and the remaining V dopants can regulate the electronic structure of NiV oxyhydroxides, which leads to enhanced kinetics for the adsorption of *OH and deprotonation of *OOH intermediates. Raman spectroscopy and X‐ray absorption spectroscopy further demonstrate that the increased content of active β‐NiOOH phase with the disordered Ni active sites contributes to OER activity enhancement. Density functional theory calculations verify that the V dopants facilitate the generation of *O intermediates during OER, which is the rate‐determining step for realizing efficient O 2 evolution. Optimization of these properties endows the NiV oxyhydroxide electrode with a low overpotential of 221 mV to deliver a current density of 10 mA cm −2 and excellent stability in the alkaline electrolyte.
Publisher: Wiley
Date: 07-12-2018
Publisher: Elsevier BV
Date: 02-2022
Publisher: Wiley
Date: 17-04-2019
Abstract: Polynary single-atom structures can combine the advantages of homogeneous and heterogeneous catalysts while providing synergistic functions based on different molecules and their interfaces. However, the fabrication and identification of such an active-site prototype remain elusive. Here we report isolated diatomic Ni-Fe sites anchored on nitrogenated carbon as an efficient electrocatalyst for CO
Publisher: Wiley
Date: 24-09-2021
Abstract: Atomically dispersed nickel–nitrogen–carbon (Ni‐N‐C) moieties are promising for efficient electrochemical CO 2 ‐to‐CO conversion. To improve the intrinsic electrocatalytic activity, it is essential but challenging to steer the coordination environment of Ni centers for promoting the CO formation kinetics. Here, we introduce alien sulfur atoms to tune the local electronic density of unsaturated NiN 2 species. A coordinated structure evolution is detected and S vacancies are generated at high overpotentials, as confirmed by X‐ray absorption spectroscopy. The sulfur dopants enhance CO selectivity and activity over normal unsaturated NiN 2 structure, reaching a high CO Faradaic efficiency of 97 % and a large CO current density of 40.3 mA cm −2 in a H‐cell at −0.8 V and −0.9 V (vs. RHE), respectively. DFT calculations reveal both doped S atoms and evolved S vacancies in the NiN 2 coordination environment contribute to the reduced energy barriers for CO 2 electroreduction to CO.
Publisher: Wiley
Date: 10-08-2023
Abstract: Electrocatalysts are crucial to drive the electrochemical carbon dioxide reduction reaction (CO 2 RR) which lower the energy barrier, tune the intricate reaction pathways and suppress competitive side‐reaction. Beyond the efficient active sites and advantageous local environment, a rapid mass transfer ability is also crucial for the catalyst design. However, it is rare that research has been done to investigate in detail the mass transfer process in CO 2 RR, and expose the underlying relationship between mass transfer and final performance. Here, a single‐atom Fe‐N‐C catalyst is shown with a highly ordered porous substrate containing hierarchical micropores, mesopores, and macropores. Such a delicate porous structure significantly facilitates the mass transfer process toward the isolated Fe sites, achieving excellent CO 2 RR performance, especially in the limited mass transfer region in a H‐cell with a maximum CO partial current density of ‐19 mA cm −2 . Operando electrochemical impedance spectroscopy and relevant distributed relaxation times analysis reveal the rapidly decreased mass transfer resistance with the increase of reduction potential. The Lattice Boltzmann method with Discrete Element method (LBM‐DEM) simulations are further performed to exhibit the origin of enhanced CO 2 RR performance from the facilitated gas diffusion process.
Publisher: Elsevier BV
Date: 05-2023
Publisher: American Chemical Society (ACS)
Date: 30-05-2018
Publisher: Wiley
Date: 12-11-2021
Abstract: An ideal catalytic interface for photoelectrodes that enables high efficiency and long‐term stability remains one of the keys to unlocking high‐performance solar water splitting. Here, fully decoupled catalytic interfaces realized using surface‐structured cocatalyst foils are demonstrated, allowing optimized photoabsorbers to be combined with high‐performance earth‐abundant cocatalysts. Since many earth‐abundant cocatalysts are deposited via solution‐based methods, deposition on chemical‐sensitive photoabsorbers is a significant challenge. By synthesizing cocatalyst foils prior to device fabrication, photoabsorbers are completely isolated from corrosive chemical environments and are provided with outstanding protection during operation. Si and GaAs photoelectrodes prepared using Ni‐based cocatalyst foils achieve excellent half‐cell efficiencies and generate stable photocurrents for over 5 days. Furthermore, a GaAs artificial leaf achieves a solar‐to‐hydrogen efficiency of 13.6% and maintains an efficiency of over 10% for longer than nine days, an accomplishment that has not been previously reported for an immersed solar water splitting system. These results, together with theoretical calculations of other photoelectrode systems, demonstrate that cocatalyst foils offer a very attractive method for fabricating high‐performance solar water splitting systems.
Publisher: Elsevier BV
Date: 08-2023
Publisher: Wiley
Date: 27-04-2022
Abstract: Modulating the electronic structure of atomically dispersed active sites is promising to boost catalytic activity but is challenging to achieve. Here we show a cooperative Ni single‐atom‐on‐nanoparticle catalyst (NiSA/NP) prepared via direct solid‐state pyrolysis, where Ni nanoparticles donate electrons to Ni(i)−N−C sites via a network of carbon nanotubes, achieving a high CO current density of 346 mA cm −2 at −0.5 V vs RHE in an alkaline flow cell. When coupled with a NiFe‐based anode in a zero‐gap membrane electrolyzer, the catalyst delivers an industrially relevant CO current density of 310 mA cm −2 at a low cell voltage of −2.3 V, corresponding to an overall energy efficiency of 57 %. The superior CO 2 electroreduction performance is attributed to the enhanced adsorption of key intermediate COOH* on the electron‐rich Ni single atoms, as well as a high density of active sites.
Publisher: Wiley
Date: 10-09-2020
DOI: 10.1002/CEY2.79
Abstract: Electrochemical water splitting has attracted considerable attention for the production of hydrogen fuel by using renewable energy resources. However, the sluggish reaction kinetics make it essential to explore precious‐metal‐free electrocatalysts with superior activity and long‐term stability. Tremendous efforts have been made in exploring electrocatalysts to reduce the energy barriers and improve catalytic efficiency. This review summarizes different categories of precious‐metal‐free electrocatalysts developed in the past 5 years for alkaline water splitting. The design strategies for optimizing the electronic and geometric structures of electrocatalysts with enhanced catalytic performance are discussed, including composition modulation, defect engineering, and structural engineering. Particularly, the advancement of operando/in situ characterization techniques toward the understanding of structural evolution, reaction intermediates, and active sites during the water splitting process are summarized. Finally, current challenges and future perspectives toward achieving efficient catalyst systems for industrial applications are proposed. This review will provide insights and strategies to the design of precious‐metal‐free electrocatalysts and inspire future research in alkaline water splitting.
Publisher: Elsevier BV
Date: 12-2022
Publisher: Wiley
Date: 30-10-2014
Abstract: The trans‐activator of transcription (TAT) peptide is regarded as the “gold standard” for cell‐penetrating peptides, capable of traversing a mammalian membrane passively into the cytosolic space. This characteristic has been exploited through conjugation of TAT for applications such as drug delivery. However, the process by which TAT achieves membrane penetration remains ambiguous and unresolved. Mechanistic details of TAT peptide action are revealed herein by using three complementary methods: quartz crystal microbalance with dissipation (QCM‐D), scanning electrochemical microscopy (SECM) and atomic force microscopy (AFM). When combined, these three scales of measurement define that the membrane uptake of the TAT peptide is by trans‐membrane insertion using a “worm‐hole” pore that leads to ion permeability across the membrane layer. AFM data provided nanometre‐scale visualisation of TAT punctuation using a mammalian‐mimetic membrane bilayer. The TAT peptide does not show the same specificity towards a bacterial mimetic membrane and QCM‐D and SECM showed that the TAT peptide demonstrates a disruptive action towards these membranes. This investigation supports the energy‐independent uptake of the cationic TAT peptide and provides empirical data that clarify the mechanism by which the TAT peptide achieves its membrane activity. The novel use of these three biophysical techniques provides valuable insight into the mechanism for TAT peptide translocation, which is essential for improvements in the cellular delivery of TAT‐conjugated cargoes including therapeutic agents required to target specific intracellular locations.
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 12-2020
Publisher: American Chemical Society (ACS)
Date: 29-10-2020
Publisher: American Chemical Society (ACS)
Date: 15-11-2017
Abstract: By introducing chromium into a nickel-iron layered double hydroxide (LDH), a nickel iron chromium hydroxide nanomesh catalyst has been achieved on nickel foam substrate via electrodeposition followed by partial etching of chromium. The electrodeposited chromium acts as a sacrificial template to introduce holes in the LDH to increase the electrochemically active surface area, and the remaining chromium synergistically modulates the electronic structure of the composite. The obtained electrode shows extraordinary performance for oxygen evolution reaction and excellent electrochemical stability. The onset potential of the as-prepared electrode in 1 M KOH is only 1.43 V vs RHE, and the overpotential to achieve a high current density of 100 mA·cm
Location: Spain
No related grants have been discovered for Jordan Gacutan.