ORCID Profile
0000-0003-1457-2491
Current Organisations
University of York
,
National University of Sciences and Technology
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Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C7GC02627G
Abstract: Nanoscale Fe 2 O 3 -catalyzed environmentally benign synthesis of nitriles and amides has been performed from easily accessible aldehydes and ammonia using O 2 .
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3AN00464C
Abstract: Cyclic voltammetry (CV), synchrotron radiation-X-ray photoelectron spectroscopy (SR-XPS) and near edge X-ray absorption fine structure (NEXAFS) show that oxidation of ferrocene tagged PVC induces an accumulation of high molecular weight polymer at the buried interface between the substrate electrode and the plasticized membrane.
Publisher: Informa UK Limited
Date: 11-02-2022
Publisher: Wiley
Date: 06-2009
Publisher: Pleiades Publishing Ltd
Date: 2017
Publisher: International Union of Crystallography (IUCr)
Date: 17-09-2005
Publisher: MDPI AG
Date: 17-09-2020
DOI: 10.3390/NANO10091856
Abstract: Whitlockite, being the second most abundant bio-mineral in living bone, finds huge applications in tissue regeneration and implants and its synthesis into its pure form has remained a challenge. Although precipitation of whitlockite phase has been reported recently in many publications, effects of various parameters to control such phase as well as conditions for the bulk preparation of this extremely important bio-mineral have not been investigated so far. In this work, we report the precipitation of pure whitlockite phase using common precursors. As reported in the literature, whitlockite is stable in a narrow pH range, therefore optimization of pH for the stabilization of whitlockite phase has been investigated. Additionally, in order to narrow down the optimum conditions for the whitlockite precipitation, effect of temperature and heating conditions has also been studied. The obtained solids were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). From PXRD analysis, it was observed that heating the precursor’s mixture at 100 °C with subsequent aging at the optimized pH resulted in the precipitation of pure whitlockite phase. These results were further confirmed by TGA, SEM and Raman spectroscopy analysis and it was confirmed that the conditions reported here favor whitlockite precipitation without formation of any secondary phase. These reaction conditions were further confirmed by changing all the parameters like aging, heating time, feed rate of precursors one by one. From PXRD analysis of these s les, it was concluded that not only pH but temperature, heating time, aging time and feed rate effect simultaneously on the precipitation of pure whitlockite phase and a subtle change in any of these parameters could lead to the formation of undesired stable secondary calcium phosphate phases.
Publisher: Frontiers Media SA
Date: 09-05-2022
DOI: 10.3389/FCHEM.2022.906031
Abstract: In this study, Ag@In 2 O 3 modified nickel foam (NF) was reported for its role as a non-enzymatic glucose sensor. Ag@In 2 O 3 was prepared by a simple two-step method preparation of a metal-organic framework (MOF) MIL-68(In) by solvothermal method, entrapment of Ag + by adding AgNO 3 then drying it for 2 h to complete the entrapment process and subsequent calcination at 650°C for 3 h. The Ag@In 2 O 3 modified NF was employed as a non-enzymatic glucose sensor to determine glucose concentrations in an alkaline medium. Two linear ranges were obtained from Ag@In 2 O 3 modified electrode, i.e., 10 μM to 0.8 mM and 0.8–2.16 mM with a sensitivity of 3.31 mA mM −1 cm −2 and 1.51 mA mM −1 cm −2 respectively, with a detection limit of 0.49 µM. Ag@In 2 O 3 modified NF exhibited high selectivity for glucose, among other interfering agents.
Publisher: Elsevier BV
Date: 08-2015
Publisher: American Chemical Society (ACS)
Date: 27-06-2012
DOI: 10.1021/AC301096R
Abstract: Seawater analysis is one of the most challenging in the field of environmental monitoring, mainly due to disparate concentration levels between the analyte and the salt matrix causing interferences in a variety of analytical techniques. We propose here a miniature electrochemical s le pretreatment system for a rapid removal of NaCl utilizing the coaxial arrangement of an electrode and a tubular Nafion membrane. Upon electrolysis, chloride is deposited at the Ag electrode as AgCl and the sodium counterions are transported across the membrane. This cell was found to work efficiently at potentials higher than 400 mV in both stationary and flow injection mode. Substantial residual currents observed during electrolysis were found to be a result of NaCl back diffusion from the outer side of the membrane due to insufficient permselectivity of the Nafion membrane. It was demonstrated that the residual current can be significantly reduced by adjusting the concentration of the outer solution. On the basis of ion chromatography results, it was found that the designed cell used in flow injection electrolysis mode reduced the NaCl concentration from 0.6 M to 3 mM. This attempt is very important in view of nutrient analysis in seawater where NaCl is a major interfering agent. We demonstrate that the pretreatment of artificial seawater s les does not reduce the content of nitrite or nitrate ions upon electrolysis. A simple diffusion/extraction steady state model is proposed for the optimization of the electrolysis cell characteristics.
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9DT00242A
Abstract: In this study, a facile and potentially scalable synthesis of AgBiS 2 (schapbachite) using melts of metal xanthates is presented AgBiS 2 is both a significant mineral and a technologically important material.
Publisher: Wiley
Date: 12-08-2015
Publisher: Elsevier BV
Date: 11-2019
Publisher: International Union of Crystallography (IUCr)
Date: 31-01-2006
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.ULTSONCH.2017.02.029
Abstract: This article presented the synthesis of a hybrid nanoarchitecture material composed of reduced graphene oxide (RGO) multiple sheets and ZnO nanowire arrays (NWAs) formed on an arbitrary ZnO coated fluorine doped tin oxide (FTO) substrates via pulse sonication and hydrothermal approach. The NWAs have high aspect-ratio, high density, apt positioning and well-ordered formation. FESEM images demonstrated that RGO layers have been effectively intercalated between and on the accessible surfaces of the ZnO NWAs. The diameter of ZnO nanowires is 80-150nm and length about 1-2μm. Raman spectrum of hybrid material exhibited characteristic D and suppressed G peaks for graphene and E
Publisher: Elsevier BV
Date: 09-2020
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8SC02807A
Abstract: Pyrolysis of cobalt-terephthalic acid MOF template on carbon produces highly active and selective cobalt nanoparticles-based hydrogenation catalysts.
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.JCIS.2022.08.067
Abstract: The high selectivity in the hydrogenation reactions of α, β-unsaturated aldehydes is always a demanding task. Precious Pt-based catalysts play a pivotal role in selective catalytic hydrogenation of α, β-unsaturated aldehydes, but controlling the selectivity is still a great challenge. Herein, the Pt nanoparticles were encaged within the mesopores of amines (-NH
Publisher: Elsevier BV
Date: 09-2013
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2RA01954J
Abstract: Illustrating the synthesis of doped and undoped CeO 2 nanomaterial and its potential application as a promising catalyst for additives to minimize emissions from spark ignition (SI) engines fueled with gasoline blends.
Publisher: Elsevier BV
Date: 07-2008
Publisher: Springer Science and Business Media LLC
Date: 05-2006
Publisher: Elsevier BV
Date: 07-2021
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/CH16072
Abstract: Ketoconazole (KCZ) is an extensively used antifungal compound and is an active ingredient of anti-scaling sh oos, pomades, and skin ointments. In this work, the cyclic voltammetric behaviour of KCZ was studied with a gold nanoparticle (AuNP)-modified glassy carbon (GC) electrode. The conditions for KCZ determination with GC/AuNP were optimised to achieve the best possible response. A pre-adsorption voltage of –1.6 V, a deposition time of 120 s, pH 4.0, and stirring of the KCZ solution during deposition were chosen as the optimum conditions for KCZ determination. The anodic peak at 0.697 V was used for KCZ determination. A linear concentration range of 20–100 μM (R2 = 0.9986) and a detection limit of 2.3 μM (3σ) was achieved for KCZ using the GC/AuNP electrode.
Publisher: International Union of Crystallography (IUCr)
Date: 18-12-2004
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6DT01016D
Abstract: A CoTiO 3 –TiO 2 composite electrode fabricated from single source precursor [Co 2 Ti 4 (μ-O) 6 (TFA) 8 (THF) 6 ]·THF is tested for electrochemical detection of dopamine.
Publisher: Wiley
Date: 13-12-2011
Publisher: Wiley
Date: 27-05-2022
DOI: 10.1002/APP.52636
Abstract: We report the synthesis and electrocatalytic activity of poly(3‐hexylthiophene) stabilized nickel oxide nanoparticles (P3HT@NiO NPs). Employing semiconducting P3HT as a stabilizing agent produced well dispersed P3HT@NiO NPs with uniform size distribution (2.5 ± 1.2 nm). For comparison, NiO NPs stabilized with the small molecule 3‐hexylthiophene (3HT@NiO NPs) were also synthesized and characterized as reference material. The physiochemical properties of the developed hybrid P3HT@NiO were fully characterized using UV/Vis absorption spectroscopy, fluorescence spectroscopy, high resolution transmission electron microscopy (HRTEM) and X‐ray photoelectron spectroscopy (XPS). The electrocatalytic activities of the developed semiconducting polymer‐stabilized NPs were evaluated for the oxygen evolution reaction (OER) of water splitting. Our work reveals the electronic communication between P3HT and NiO NPs and demonstrates that P3HT@NiO NPs exhibit superior catalytic activity with an overpotential of 310 mV when compared to the reference 3HT@NiO NPs which exhibited an overpotential 560 mV. These results suggest that the heteroatom‐containing π‐conjugated semiconducting polymers can be employed as electrocatalytic performance enhancing and stabilizing ligands for the synthesis of ultrafine metal‐based NPs as efficient electrocatalytic platforms.
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6RA15134E
Abstract: This work studied a new way of sensing oil leaks using graphene foam through an optical imaging and light scattering method.
Publisher: Springer Science and Business Media LLC
Date: 02-10-2014
Publisher: MDPI AG
Date: 24-04-2021
DOI: 10.3390/NANO11051105
Abstract: This research aims to synthesize the Bis(di-isobutyldithiophosphinato) nickel (II) complex [Ni(iBu2PS2)] to be employed as a substrate for the deposition of nickel sulfide nanostructures, and to investigate its dielectric and impedance characteristics for applications in the electronic industry. Various analytical tools including elemental analysis, mass spectrometry, IR, and TGA were also used to further confirm the successful synthesis of the precursor. NiS nanostructures were grown on the glass substrates by employing an aerosol assisted chemical vapor deposition (AACVD) technique via successful decomposition of the synthesized complex under variable temperature conditions. XRD, SEM, TEM, and EDX methods were well applied to examine resultant nanostructures. Dielectric studies of NiS were carried out at room temperature within the 100 Hz to 5 MHz frequency range. Maxwell-Wagner model gave a complete explanation of the variation of dielectric properties along with frequency. The reason behind high dielectric constant values at low frequency was further endorsed by Koops phenomenological model. The efficient translational hopping and futile reorientation vibration caused the overdue exceptional drift of ac conductivity (σac) along with the rise in frequency. Two relaxation processes caused by grains and grain boundaries were identified from the fitting of a complex impedance plot with an equivalent circuit model (Rg Cg) (Rgb Qgb Cgb). Asymmetry and depression in the semicircle having center present lower than the impedance real axis gave solid justification of dielectric behavior that is non-Debye in nature.
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4428999
Publisher: American Chemical Society (ACS)
Date: 19-09-2022
Publisher: Elsevier BV
Date: 2024
Publisher: Wiley
Date: 19-01-2022
Abstract: Transition metal nitrides have attracted great interest among the non‐noble catalysts employed in heterogeneous catalytic processes because of their exceptional stability and catalytic potential. However, the approach for their synthesis has remained a tremendous challenge. This study presents the synthesis of Co 4 N/C catalyst fabricated at 400, 600, and 800 °, symbolized as Co 4 N/C‐400, Co 4 N/C‐600, Co 4 N/C‐800, respectively. The characterization of fabricated catalysts is carried out through various advanced analytical techniques. As prepared nano‐catalyst Co 4 N/C shows remarkable catalytic efficiency in terms of low activation energy ( E a =3.038×10 −1 KJ mol −1 ), fast conversion rate ( K app =0.2884 s −1 ), and 97.57% conversion efficiency. Moreover, it also exhibits excellent stability and reusability because of its metallic characteristics. The outstanding catalytic activity of the catalyst is the combined effect in which the Co 4 N nanoparticles acted as active sites, and the carbon support doped with nitrogen provided an expressway for the transport of electrons required for catalytic reduction. Moreover, the designed catalyst is immobilized on the cellulose membrane filter support, to demonstrate the catalytic reduction of 4‐nitrophenol to 4‐aminophenol. We envision that our work would facilitate the fabrication of cobalt nitrides‐based nano‐catalysts for a wide range of industrial applications.
Publisher: Elsevier BV
Date: 04-2015
Publisher: Slovenian Chemical Society
Date: 15-12-2018
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 09-2014
DOI: 10.1016/J.EJMECH.2014.07.028
Abstract: Fourteen new organotin(IV) complexes with general formula R2SnL2 or R3SnL where R = CH3, C2H5, C4H9, C6H5, C6H11, CH2-C6H5, C(CH3)3, C8H17 and L = N-[(2-methoxyphenyl)]-4-oxo-4-[oxy]butanamide were synthesized and characterized by elemental analyses, FT-IR, NMR ((1)H, (13)C and (119)Sn), mass spectrometry and single crystal X-ray structural analysis. Crystallographic data for four triorganotin(IV) complexes (R3SnL, R = CH3, C2H5, C4H9, CH2-C6H5) showed the tin has approximate trigonal bipyramidal geometry with the R groups in the trigonal plane. The carboxylate groups of ligands L bridge adjacent tin atoms, resulting in polymeric chains. In case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic evidence. The Me-Sn-Me bond angle in complex 7 was determined from the (2)J[(119)Sn-(1)H] value as 166.3° that falls in the range of six-coordinate geometry. The ligand and its complexes (1-14) were screened for their antimicrobial, antitumor, cytotoxic and antileishmanial activities and found to be biologically active. The ligand and its complexes bind to DNA via intercalative interactions resulting in hypochromism and minor bathochromic shifts as confirmed by UV-visible spectroscopy. Based on in vitro studies such as the potato disc method, the synthesized compounds were found to possess significant antitumor activity. Also, from cytotoxicity and DNA interaction studies, these compounds can also be used for the prevention and treatment of cancer. Gel electrophoresis assay was used to investigate the damage to double stranded super coiled plasmid pBR322 DNA by the synthesized compounds and compounds 1 and 7 were found to cause the maximum damage. All the synthesized compounds exhibit strong antileishmanial activity that was even higher than that of Amphotericin B, with significant cytotoxicity. This study, therefore, demonstrated the potential use of these compounds as source of novel agents for the treatment of leishmaniasis.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NJ01507D
Abstract: Metal–organic frameworks (MOFs) as direct electrode materials for electrochemical sensing can offer inherent advantages such as containing sensing element and redox mediator in a single molecule.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 08-2015
Publisher: American Chemical Society (ACS)
Date: 06-08-2019
Publisher: American Chemical Society (ACS)
Date: 30-10-2023
Publisher: Wiley
Date: 19-01-2021
Publisher: American Chemical Society (ACS)
Date: 14-09-2015
DOI: 10.1021/ACS.LANGMUIR.5B01693
Abstract: The transportation and accumulation of redox active species at the buried interface between glassy carbon electrodes and plasticized polymeric membranes have been studied using synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS), near edge X-ray absorption fine structure (NEXAFS), in situ electrochemical Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy, cyclic voltammetry (CV), chrono erometry (CA), and electrochemical impedance spectroscopy (EIS). Ferrocene tagged poly(vinyl chloride) [FcPVC], ferrocene (Fc), and its derivatives together with tetracyanoquinodimethane (TCNQ) doped plasticized polymeric membrane electrodes have been investigated, so as to extend the study of the mechanism of this reaction chemistry to different time scales (both small and large molecules with variable diffusion coefficients) using a range of complementary electrochemical and surface analysis techniques. This study also provides direct spectroscopic evidence for the transportation and electrochemical reactivity of redox active species, regardless of the size of the electrochemically reactive molecule, at the buried interface of the substrate electrode. With all redox dopants, when CA electrolysis was performed, redox active species were undetectable (<1 wt % of signature elements or below the detection limit of SR-XPS and NEXAFS) in the outermost surface layers of the membrane, while a high concentration of redox species was located at the electrode substrate as a consequence of the deposition of the reaction product (Fc(+)-anion complex) at the buried interface between the electrode and the membrane. This reaction chemistry for redox active species within plasticized polymeric membranes may be useful in the fashioning of multilayered polymeric devices (e.g., chemical sensors, organic electronic devices, protective laminates, etc.) based on an electrochemical tunable deposition of redox molecules at the buried substrate electrode beneath the membrane.
Publisher: Elsevier BV
Date: 10-2018
Publisher: Elsevier BV
Date: 02-2019
Publisher: Elsevier BV
Date: 04-2023
Publisher: Wiley
Date: 12-03-2015
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 10-2017
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/D0RA04571C
Abstract: A modified co-precipitation method has been used for the synthesis of PdO–2Mn 2 O 3 nanocomposite as an efficient electrode material for the electro-catalytic oxygen evolution (OER) and hydrogen evolution reaction (HER).
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8DT00285A
Abstract: A new organo tin complex has been synthesized and used as a single source precursor for the synthesis of tin selenide nanosheets and deposition of thin films.
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 06-2013
Publisher: Wiley
Date: 04-05-2022
Abstract: Dopamine (DA) is a neurotransmitter that plays a pivotal role in the brain's proper functioning and several other physiological processes. Herein, we demonstrate the miniaturized electrochemical sensor for detecting DA using hafnium metal‐organic framework (Hf‐MOF) derived new nanocomposite of hafnium and cobalt oxides (HfO 2 ‐CoO). Calcination of Hf‐MOF coated with cobalt acetylacetonate complex [(Co(acac) 2 ] yield HfO 2 ‐CoO nanoparticles supported over in situ generated graphitic carbon. The excellent adsorption capabilities of HfO 2 and highly catalytic CoO activity make this bimetallic HfO 2 ‐CoO nanocomposite to display a stable response over a wide linear concentration range when used as electrode material in the electrochemical DA sensing process. Moreover, the computational study also proves that CoO improves the chemisorption properties of HfO 2 for DA. Electrochemical studies are performed through cyclic voltammetry (CV), linear sweep voltammetry (LSV), and differential pulse voltammetry (DPV). For the case of LSV, the HfO 2 ‐CoO nanocomposite modified glassy carbon electrode (HfO 2 ‐CoO/GCE) exhibit a linear response to DA concentration ranging from 0.25 to 3.15 mM. However, with DPV HfO 2 ‐CoO/GCE electrode has displayed a linear range of 10–190 μM and a detection limit of 1.8 μM is achieved. The electrode has also shown excellent stability, and only 19 % loss in its initial current response is observed over 150 days of specific interval testing. The HfO 2 ‐CoO/GCE nanocomposite electrode, due to its unique feature of stability, selectivity, and sensitivity, has a good potential for use as an analytical tool for non‐enzymatic sensing of DA and other neurotransmitters in the human fluid.
Publisher: Elsevier BV
Date: 2019
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CH17187
Abstract: The transformation of cadmium 7,7,8,8-tetracyanoquinodimethane (TCNQ) into a cadmium terephthalate co-ordination polymer is reported, with the chemistry of this material elucidated using elemental analysis, X-ray photoelectron spectroscopy and synchrotron radiation single-crystal X-ray diffraction. A heptacoordinated CdII linear coordination polymer catena-poly[triaqua-(μ2-benzene-1,4-dicarboxylato-κO,O′)cadmium(ii)]hydrate (1) was isolated while attempting to recrystallize Cd(TCNQ)2. Density functional theory calculations for the oxidation of benzylic carbon attached to the cyano group provided evidence that the reaction pathway proposed herein is highly exergonic and thermodynamically plausible. This structure showed a distorted pentagonal bipyramidal geometry together with a symmetrical mononuclear unit in which each CdII ion is doubly bridged by a dicarboxylato anion. Owing to the softness and minute size of these crystals, this structure had to be elucidated using synchrotron radiation X-ray crystallography.
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4415458
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 04-2022
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 08-2017
Publisher: American Chemical Society (ACS)
Date: 10-03-2023
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6DT02656G
Abstract: Pristine Mn 2 O 3 and Ag–Mn 2 O 3 nanocomposite thin films deposited by AACVD on FTO showed photocurrent densities of 1.8 and 3 mA cm −2 respectively.
Publisher: Springer Science and Business Media LLC
Date: 21-02-2019
Publisher: MDPI AG
Date: 06-01-2023
DOI: 10.3390/MOLECULES28020572
Abstract: The rapid depletion of fossil fuels and environmental pollution has motivated scientists to cultivate renewable and green energy sources. The hydrogen economy is an emerging replacement for fossil fuels, and photocatalytic water splitting is a suitable strategy to produce clean hydrogen fuel. Herein, the photocatalyst (PdO.TiO2) is introduced as an accelerated photoelectrochemical oxygen evolution reaction (OER). The catalyst showed significant improvement in the current density magnitude from 0.89 (dark) to 4.27 mA/cm2 (light) during OER at 0.5 V applied potential. The as-synthesized material exhibits a Tafel slope of 170 mVdec−1 and efficiency of 0.25% at 0.93 V. The overall outcomes associated with the photocatalytic activity of PdO.TiO2 demonstrated that the catalyst is highly efficient, thereby encouraging researchers to explore more related catalysts for promoting facile OER.
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 04-2014
Publisher: Elsevier BV
Date: 02-2013
Publisher: Wiley
Date: 17-02-2011
Publisher: Frontiers Media SA
Date: 05-10-2022
DOI: 10.3389/FCHEM.2022.1014248
Abstract: Chiral Metal-Organic Frameworks (CMOFs) are unique crystalline and porous class of materials which is composed of organic linkers and metal ions. CMOFs surpass traditional organic and inorganic porous materials because of their tunable shape, size, functional ersity, and selectivity. Specific applications of CMOFs may be exploited by introducing desired functional groups. CMOFs have chiral recognition abilities, making them unique for chiral compound synthesis and separation. The CMOFs can be synthesized through different approaches. Two main approaches have been discussed, i.e., direct and indirect synthesis. Synthetic strategies play an essential role in getting desired properties in MOFs. CMOFs find potential applications in adsorption, asymmetric catalysis, luminescence, degradation, and enantioselective separation. The MOFs’ porosity, stability, and reusability make them an attractive material for these applications. The plethora of applications of CMOFs have motivated chemists to synthesize novel MOFs and number of MOFs have been ever-escalating. Herein, the synthetic methods of CMOFs and their various applications have been discussed.
Publisher: Springer Science and Business Media LLC
Date: 03-03-2021
DOI: 10.1038/S41598-021-84294-7
Abstract: Non-enzymatic electrochemical detection of catechol (CC) and hydroquinone (HQ), the xenobiotic pollutants, was carried out at the surface of novel carbon nanocoils/zinc-tetraphenylporphyrin (CNCs/Zn-TPP) nanocomposite supported on glassy carbon electrode. The synergistic effect of chemoresponsive activity of Zn-TPP and a large surface area and electron transfer ability of CNCs lead to efficient detection of CC and HQ. The nanocomposite was characterized by using FT-IR, UV/vis. spectrophotometer, SEM and energy dispersive X-ray spectroscopy (EDS). Cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used for the electrochemical studies. CNCs/Zn-TPP/GCE nanosensor displayed a limit of detection (LOD), limit of quantification (LOQ) and sensitivity for catechol as 0.9 µM, 3.1 µM and 0.48 µA µM −1 cm −2 , respectively in a concentration range of 25–1500 µM. Similarly, a linear trend in the concentration of hydroquinone detection was observed between 25 and 1500 µM with an LOD, LOQ and sensitivity of 1.5 µM, 5.1 µM and 0.35 µA µM −1 cm −2 , respectively. DPV of binary mixture pictured well resolved peaks with anodic peak potential difference, ∆E pa(CC-HQ), of 110 mV showing efficient sensing of CC and HQ. The developed nanosensor exhibits stability for up to 30 days, better selectivity and good repeatability for eight measurements (4.5% for CC and 5.4% for HQ).
Publisher: Wiley
Date: 15-01-2018
Abstract: Metal-organic frameworks (MOFs) are class of porous materials that can be assembled in a modular manner by using different metal ions and organic linkers. Owing to their tunable structural properties, these materials are found to be useful for gas storage and separation technologies, as well as for catalytic applications. A cost-effective zinc-based MOF ([Zn(bpcda)(bdc)]
Publisher: MDPI AG
Date: 23-10-2021
DOI: 10.3390/NANO11112817
Abstract: This research endeavor aimed to synthesize the lead (II) diphenyldiselenophosphinate complex and its use to obtain lead selenide nanostructured depositions and further the impedance spectroscopic analysis of these obtained PbSe nanostructures, to determine their roles in the electronics industry. The aerosol-assisted chemical vapor deposition technique was used to provide lead selenide deposition by decomposition of the complex at different temperatures using the glass substrates. The obtained films were revealed to be a pure cubic phase PbSe, as confirmed by X-ray diffraction analysis. SEM and TEM micrographs demonstrated three-dimensionally grown interlocked or aggregated nanocubes of the obtained PbSe. Characteristic dielectric measurements and the impedance spectroscopy analysis at room temperature were executed to evaluate PbSe properties over the frequency range of 100 Hz–5 MHz. The dielectric constant and dielectric loss gave similar trends, along with altering frequency, which was well explained by the Koops theory and Maxwell–Wagner theory. The effective short-range translational carrier hopping gave rise to an overdue remarkable increase in ac conductivity (σac) on the frequency increase. Fitting of a complex impedance plot was carried out with an equivalent circuit model (Rg Cg) (Rgb Qgb Cgb), which proved that grains, as well as grain boundaries, are responsible for the relaxation processes. The asymmetric depressed semicircle with the center lower to the impedance real axis provided a clear explanation of non-Debye dielectric behavior.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Informa UK Limited
Date: 14-08-2020
Publisher: American Chemical Society (ACS)
Date: 14-08-2019
Publisher: Elsevier BV
Date: 05-2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NJ00188F
Abstract: Crystal engineering is an effective route for synthesis of mixed ligand metal–organic frameworks with attractive topologies and versatile potential applications.
Publisher: MDPI AG
Date: 15-01-2023
DOI: 10.3390/MEMBRANES13010113
Abstract: The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H2O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H2) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies.
Publisher: American Chemical Society (ACS)
Date: 19-01-2021
Publisher: Wiley
Date: 08-01-2016
Publisher: Wiley
Date: 04-05-2021
Abstract: A new organic‐inorganic hybrid salt of cyclohexylammonium hexaisothiocyanatochromate(III) sesquihydrate, (C 6 H 11 NH 3 ) 3 [Cr(NCS) 6 ] ⋅ 3/2H 2 O, was synthesized at room‐temperature by metathesis and ligand addition for the establishment of energy‐saving chemical synthesis approach. The formation of this new salt was confirmed by FT‐IR, UV‐Vis spectrophotometry, elemental microanalysis, and single‐crystal X‐ray diffraction. The TGA study showed low‐temperature thermal stability of this salt, where chromium oxide (Cr 2 O 3 ) formed under air and chromium sulfide (Cr 2 S 3 ) under argon, as PXRD confirmed their formation as nanocrystalline. The morphological studies by SEM and TEM revealed the formation of irregular polyhedron particles of Cr 2 O 3 and of hexagonal packed layers of Cr 2 S 3 . The textural study by nitrogen physisorption disclosed the mesoporous nature and high specific surface area of Cr 2 O 3 (∼132 m 2 g −1 ) and Cr 2 S 3 (∼241 m 2 g −1 ). Cyclohexylammonium could act as an organic self‐template for the formation of mesopores and the high temperature of thermolysis assisted the formation of such pores.
Publisher: Wiley
Date: 13-02-2017
DOI: 10.1002/APP.44948
Publisher: American Chemical Society (ACS)
Date: 18-03-2020
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 09-2012
DOI: 10.1016/J.ACA.2012.07.026
Abstract: A nitrate ion-selective electrode (ISE) employing a permeable tubular membrane impregnated with a conventional ISE cocktail has been used successfully in the coulometric analysis of nitrate in fresh waters. The liquid ISE membrane comprising a nitrate ionophore [tridodecylmethylammonium nitrate (TDMAN)], lipophilic electrolyte [tetradodecyl-ammoniumtetrakis(4-chlorophenyl)borate (ETH 500)] and plasticizer [bis(3-ethyl-hexyl)sebacate (DOS)] was supported on a porous polypropylene tube. Coulometric analysis with the tubular membrane ISE showed that nitrate could be detected in the range 10-100 μM with a precision of 2.3% relative standard deviation (RSD), limit of detection of 1.1 μM and relative accuracy of 4.4% compared to a certified reference material (CRM) Lake s le.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Wiley
Date: 16-05-2019
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 09-2020
Publisher: Elsevier BV
Date: 2019
Publisher: Royal Society of Chemistry (RSC)
Date: 2019
DOI: 10.1039/C9TA01198F
Abstract: An effcient electrocatalytic Pd system, prepared via the AACVD method, is presented executing high activity water oxidation at 1.43 V vs RHE η = 200 mV while exceeding the benchmark performance of IrO 2 .
Publisher: Springer Science and Business Media LLC
Date: 24-10-2019
DOI: 10.1038/S41598-019-51780-Y
Abstract: In direct methanol fuel cell technology, highly stable electrochemical catalysts are critically important for their practical utilization at the commercial scale. In this study, sub ~10 nm hollow Pt-Ni (1:1 at. ratio) nanoboxes supported on functionalized Vulcan carbon (Pt-Ni/C-R2) were synthesized through a facile method for the efficient electrooxidation of methanol. Two reaction procedures, namely, a simultaneous reduction and a modified sequential reduction method using a reverse microemulsion (RME) method, were adopted to synthesize solid Pt-Ni NPs and hollow nanoboxes, respectively. To correlate the alloy composition and surface structure with the enhanced catalytic activity, the results were compared with the nanocatalyst synthesized using a conventional NaBH 4 reduction method. The calculated electroactive surface area for the Pt-Ni/C-R2 nanoboxes was 190.8 m 2 .g −1 , which is significantly higher compared to that of the Pt-Ni nanocatalyst (96.4 m 2 .g −1 ) synthesized by a conventional reduction method. Hollow nanoboxes showed 34% and 44% increases in mass activity and rate of methanol oxidation reaction, respectively, compared to solid NPs. These results support the nanoreactor confinement effect of the hollow nanoboxes. The experimental results were supported by Density Functional Theory (DFT) studies, which revealed that the lowest CO poisoning of the Pt 1 Ni 1 catalyst among all Pt m -Ni n mixing ratios may account for the enhanced methanol oxidation. The synthesized hollow Pt-Ni/C (R2) nanoboxes may prove to be a valuable and highly efficient catalysts for the electrochemical oxidation of methanol due to their low cost, numerous catalytically active sites, low carbon monoxide poisoning, large electroactive surface area and long-term stability.
Publisher: Elsevier BV
Date: 2023
DOI: 10.2139/SSRN.4401395
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 12-2020
Publisher: MDPI AG
Date: 26-11-2020
DOI: 10.3390/NANO10122341
Abstract: Solar energy conversion through photoelectrochemical water splitting (PEC) is an upcoming promising technique. MoS2/CoTe heterostructures were successfully prepared and utilized for PEC studies. MoS2 and CoTe were prepared by a hydrothermal method which were then ultrasonicated with wt. % ratios of 1:3, 1:1 and 3:1 to prepare MoS2/CoTe (1:3), MoS2/CoTe (1:1) and MoS2/CoTe (3:1) heterostructure, respectively. The pure materials and heterostructures were characterized by XRD, UV–vis-DRS, SEM, XPS, PL and Raman spectroscopy. Photoelectrochemical measurements were carried out by linear sweep voltammetry and electrochemical impedance spectroscopic measurements. A maximum photocurrent density of 2.791 mA/cm2 was observed for the MoS2/CoTe (1:1) heterojunction which is about 11 times higher than the pristine MoS2. This current density was obtained at an applied bias of 0.62 V vs. Ag/AgCl (1.23 V vs. RHE) under the light intensity of 100 mW/cm2 of AM 1.5G illumination. The enhanced photocurrent density may be attributed to the efficient electron–hole pair separation. The solar to hydrogen conversion efficiency was found to be 0.84% for 1:1 MoS2/CoTe, signifying the efficient formation of the p-n junction. This study offers a novel heterojunction photocatalyst, for PEC water splitting.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 09-2022
Publisher: Springer Science and Business Media LLC
Date: 16-03-2021
Publisher: Elsevier BV
Date: 08-2014
DOI: 10.1016/J.ACA.2014.08.046
Abstract: Three new calixarene Tl(+) ionophores have been utilized in Tl(+) ion-selective electrodes (ISEs) yielding Nernstian response in the concentration range of 10(-2)-10(-6)M TlNO3 with a non-optimized filling solution in a conventional liquid contact ISE configuration. The complex formation constants (logβIL) for two of the calixarene derivatives with thallium(I) (i.e. 6.44 and 5.85) were measured using the sandwich membrane technique, with the other ionophore immeasurable due to eventual precipitation of the ionophore during these long-term experiments. Furthermore, the unbiased selectivity coefficients for these ionophores displayed excellent selectivity against Zn(2+), Ca(2+), Ba(2+), Cu(2+), Cd(2+) and Al(3+) with moderate selectivity against Pb(2+), Li(+), Na(+), H(+), K(+), NH4(+) and Cs(+), noting that silver was the only significant interferent with these calixarene-based ionophores. When optimizing the filling solution in a liquid contact ISE, it was possible to achieve a lower limit of detection of approximately 8nM according to the IUPAC definition. Last, the new ionophores were also evaluated in four solid-contact (SC) designs leading to Nernstian response, with the best response noted with a SC electrode utilizing a gold substrate, a poly(3-octylthiophene) (POT) ion-to-electron transducer and a poly(methyl methacrylate)-poly(decyl methacrylate) (PMMA-PDMA) co-polymer membrane. This electrode exhibited a slope of 58.4mVdecade(-1) and a lower detection limit of 30.2nM. Due to the presence of an undesirable water layer and/or leaching of redox mediator from the graphite redox buffered SC, a coated wire electrode on gold and graphite redox buffered SC yielded grossly inferior detection limits against the polypyrrole/PVC SC and POT/PMMA-PDMA SC ISEs that did not display signs of a water layer or leaching of SC ingredients into the membrane.
Publisher: Frontiers Media SA
Date: 21-11-2022
DOI: 10.3389/FCHEM.2022.1046930
Abstract: Tuberculosis (TB) remains a leading cause of death globally, especially in underdeveloped nations. The main impediment to TB eradication is a lack of efficient diagnostic tools for disease diagnosis. In this work, label free and ultrasensitive electrochemical DNA biosensor for detecting Mycobacterium tuberculosis has been developed based on the electrodeposition of gold nanoparticles on the surface of carbon screen-printed carbon electrode (Zensors) for signal lification. Particularly, screen-printed electrodes were modified by electrochemical deposition of Au to enhance the conductivity and facilitate the immobilization of ssDNA probes via Au-S bonds. The electrochemically modified SPEs were characterized using Scanning electron microscopy/Energy Dispersive X-Ray Analysis (SEM/EDX) and X-Ray Diffraction (XRD). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were used to investigate the DNA hybridization between single-stranded (ssDNA) probe and target DNA (tDNA). Under the ideal conditions, DPV exhibited a correlation coefficient R2 = 0.97, when analyzed with different tDNA concentrations. The proposed DNA biosensor exhibits a good detection range from 2 to 10 nm with a low detection limit of 1.91 nm, as well as high selectivity that, under ideal conditions, distinguishes non-complementary DNA from perfectly matched tDNA. By eliminating the need for DNA purification, this work paves the path for creating disposable biosensors capable of detecting DNA from raw sputum s les.
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.BIOS.2011.04.002
Abstract: A bilayer erometric nitrate biosensor with an integrated permselective layer has been developed for exclusion of inorganic anion and cation interferences. The inner PPy(polypyrrole)-NaR-NADH layer of the biosensor is formed by galvanostatic polymerization of pyrrole (Py) in presence of nitrate reductase (NaR) and nicotinamide adenine dinucleotide (NADH), followed by formation of the outer permselective poly-ortho-phenylenediamine (P-o-PDA) layer by potentiodynamic polymerization of ortho-phenylenediamine (o-PDA). The exclusion efficiency (E(eff)) of the outer layer in rejecting inorganic cation and anion interferences is evaluated by a new proposed relationship. 73-87% and 47-84% of anion and cation interferences, respectively, were efficiently rejected with the permselective layer. Further improvement in the exclusion efficiency for cations was accomplished by combining the use of the outer layer with the addition of 1mM EDTA into the measurement solution. The addition of EDTA improved the E(eff) achieved for cation rejection by 10-40% to give net E(eff) of 89-94%. The inclusion of the outer layer also aided the retention of NaR and NADH in the inner PPy-NaR-NADH layer and, hence, enabled improved erometric detection of nitrate, achieving a detection limit of 0.20 μM and a linear concentration range of 10-500 μM with a 3.4%rsd (n=10).
Publisher: Elsevier BV
Date: 12-2017
Publisher: Elsevier
Date: 2013
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 11-2022
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/CH15250
Abstract: A simple chemical reduction approach was used to synthesize Ag nanoparticles (NPs) over a reputed photocatalyst, Degussa P25 (TiO2). Silver doping extended the P25 absorption wavelength from the ultraviolet to the visible region. The synthesized silver NPs (Ag NPs) were of spherical shape and had an average size of ~4.6 nm. In the next stage, Ag NPs were partially oxidized by treatment with hydrogen peroxide. The resulting P25/Ag/Ag2O nanocomposites were characterized by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray analysis, Brunauer–Emmett–Teller analysis, and UV-visible spectroscopy. The photocatalytic activities of the P25, P25/Ag, and P25/Ag/Ag2O catalysts were investigated for the degradation of non-biodegradable dyes, methylene blue and rhodamine 6G. The P25/Ag/Ag2O nanocomposite exhibited better photodegradation activity than P25, as well as the commonly used Ag3PO4, under visible light irradiation.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 12-2023
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.TALANTA.2016.03.002
Abstract: The inorganic nitrate (NO3‾) anion is present under a variety of both natural and artificial environmental conditions. Nitrate is ubiquitous within the environment, food, industrial and physiological systems and is mostly present as hydrated anion of a corresponding dissolved salt. Due to the significant environmental and toxicological effects of nitrate, its determination and monitoring in environmental and industrial waters are often necessary. A wide range of analytical techniques are available for nitrate determination in various s le matrices. This review discusses biosensors available for nitrate determination using the enzyme nitrate reductase (NaR). We conclude that nitrate determination using biosensors is an excellent non-toxic alternative to all other available analytical methods. Over the last fifteen years biosensing technology for nitrate analysis has progressed very well, however, there is a need to expedite the development of nitrate biosensors as a suitable alternative to non-enzymatic techniques through the use of different polymers, nanostructures, mediators and strategies to overcome oxygen interference.
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.EJMECH.2015.03.019
Abstract: Two new gold(I) complexes that contain tri-ter-butylphosphine and dialkyl dithiocarbamate ligands were synthesized and characterized by FTIR, NMR spectroscopy, Cyclic voltammetry, elemental analysis and X-ray diffraction. The in vitro cytotoxicity of both complexes was examined against A549 (lung cancer), MCF7 (breast cancer), and HeLa (cervical cancer) human cancer cell lines. Both complexes exhibit very strong in vitro cytotoxic effects against A549, MCF7 and HeLa cell lines. The screening of the cytotoxic activity based on IC50 data against the A549, MCF7, and HeLa lines shows that the synthesized gold(I) complexes are highly effective, particularly against HeLa cancer cell line. Based on IC50 data, the cytotoxic activity of both complexes is better than well-known commercial anticancer drug cisplatin against all the three cancer lines tested.
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 07-2023
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 06-2021
Publisher: Springer Science and Business Media LLC
Date: 28-01-2022
DOI: 10.1038/S41467-021-27895-0
Abstract: Under normal conditions, the most significant expansion and differentiation of the adult mammary gland occurs in response to systemic reproductive hormones during pregnancy and lactation to enable milk synthesis and secretion to sustain the offspring. However, human mammary tissue remodelling that takes place during pregnancy and lactation remains poorly understood due to the challenge of acquiring s les. We report here single-cell transcriptomic analysis of 110,744 viable breast cells isolated from human milk or non-lactating breast tissue, isolated from nine and seven donors, respectively. We found that human milk largely contains epithelial cells belonging to the luminal lineage and a repertoire of immune cells. Further transcriptomic analysis of the milk cells identified two distinct secretory cell types that shared similarities with luminal progenitors, but no populations comparable to hormone-responsive cells. Taken together, our data offers a reference map and a window into the cellular dynamics that occur during human lactation and may provide further insights on the interplay between pregnancy, lactation and breast cancer.
Publisher: Frontiers Media SA
Date: 15-10-2020
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 03-2019
Publisher: Informa UK Limited
Date: 19-05-2014
Publisher: Elsevier BV
Date: 06-2012
Publisher: Elsevier BV
Date: 12-2021
Publisher: MDPI AG
Date: 03-08-2020
Abstract: The fabrication of durable and low-cost nanostructured materials remains important in chemical, biologic and medicinal applications. Particularly, iron-based nanomaterials are of central importance due to the ‘noble’ features of iron such as its high abundance, low cost and non-toxicity. Herein we report a simple sol–gel method for the synthesis of novel iron–titanium nanocomposite-based material (Fe9TiO15@TiO2). In order to prepare this material, we made a polymeric gel using ferrocene, titanium isopropoxide and THF precursors. The calcination of this gel in air at 500 °C produced Fe-Ti bimetallic nanoparticles-based composite and nano-TiO2 as support. Noteworthy, our methodology provides an excellent control over composition, size and shape of the resulting nanoparticles. The resulted Fe-based material provides a sustainable catalyst for selective synthesis of anilines, which are key intermediates for the synthesis of several chemicals, dyes and materials, via reduction of structurally erse and functionalized nitroarenes.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: Saudi Arabia
No related grants have been discovered for Manzar Sohail.