@article { ISI:000347265700005, title = {Characterization, non-isothermal decomposition kinetics and photocatalytic water splitting of green chemically synthesized polyoxoanions of molybdenum containing phosphorus as hetero atom}, journal = {Thermochimica Acta}, volume = {596}, year = {2014}, month = {NOV}, pages = {29-36}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

In here, the green synthesis and thermal characterization of a novel polyoxoanions of molybdenum containing phosphorus as hetero atom are reported. The composition and morphology of the nanorods were established by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and inductively coupled plasma atomic emission spectroscopic (ICP-AES) techniques. Thermal properties of the nanoparticles were investigated by non-isothermal analysis under nitrogen atmosphere. The values activation energy of each stage of thermal decomposition for all heating rates was calculated by Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunnose (KAS) methods. Invariant kinetic parameter (IKP) method and master plot methodmere also used to evaluate the kinetic parameters and mechanism for the thermal decomposition of cetylpyridinium phosphomolybdate (CPM). Photocatalytic water oxidation mechanism using CPM catalyst in the presence of platinum (Pt) co-catalyst enhances the H-2 evolution and was found to be 1.514 mmol/g/h. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Keggin structure, Master plot method, Polyoxometalate, Water oxidation}, issn = {0040-6031}, doi = {10.1016/j.tca.2014.09.010}, author = {D{\textquoteright}Cruz, Bessy and Samuel, Jadu and George, Leena} } @article {43899, title = {Copper Cobalt Sulfide Nanosheets Realizing a Promising Electrocatalytic Oxygen Evolution Reaction}, journal = {ACS Catalysis}, volume = {7}, year = {2017}, month = {SEP}, chapter = {5871-5879}, abstract = {

Nanostructured CuCo2S4, a mixed metal thiospinel, is found to be a benchmark electrocatalyst for oxygen evolution reaction (OER) in this study with a low overpotential, a low Tafel slope, a high durability, and a high turnover frequency (TOF) at lower mass loadings. Nanosheets of CuCo2S4 are realized from a hydrothermal synthesis method in which the average thickness of the sheets is found to be in the range of 815 nm. Aggregated nanosheets form a highly open hierarchical structure. When used as an electrocatalyst, CuCo2S4 nanosheets offer an overpotential value of 310 mV at a 10 mA cm(2) current density, which remains consistent for 10000 measured cycles in a 1 M KOH electrolyte. A chronoamperometric study reveals constant oxygen evolution for 12 h at a 10 mV s(-1) scan rate without any degradation of the activity. Furthermore, the calculated mass activity of the CuCo2S4 electrocatalyst is found to be 14.29 A/g and to afford a TOF value of 0.1431 s(-1) at 310 mV at a mass loading of 0.7 mg cm(-2). For comparison, nanostructures of Co3S4 and Cu0.5Co2.5S4 have been synthesized using a similar method followed for CuCo2S4. When compared to the OER activities among these three thiospinels and standard IrO2, CuCo2S4 nanosheets offered the highest OER activities at the same mass loading (0.7 mg/cm(-2)). Extensive X-ray photoelectron spectroscopy and electron paramagnetic resonance analyses for a mechanistic study reveal that introduction of Cu into the Co3S4 lattice enhances the oxygen evolution and kinetics by offering Cu2+ sites for utilitarian adsorption of OH, O, and OOH reactive species and also by offering a highly active high-spin state of octahedral Co3+ for OER catalysis.

}, keywords = {Bifunctional Electrocatalyst, Catalyst, Cuco2s4, Efficient Electrocatalyst, electrocatalyst, Electronic-structure, Nanoparticles, Nanosheet, oxide, oxygen evolution, performance, Recent Progress, Water oxidation, Water Splitting Hydrogen Evolution}, doi = { 10.1021/acscatal.7b01831}, author = {Chauhan, Meenakshi and Reddy, Kasala Prabhakar and Gopinath, Chinnakonda S. and Deka, Sasanka} } @article {47759, title = {Facile fabrication of nano silver phosphate on B-doped g-C3N4: an excellent p-n heterojunction photocatalyst towards water oxidation and Cr (VI) reduction}, journal = {Journal of Alloys and Compounds}, volume = {898}, year = {2022}, month = {MAR}, pages = {162853}, type = {Article}, abstract = {A photostable Ag3PO4/BCN type-II p-n heterojunction has been demonstrated by loading nano Ag3PO4 on B-doped g-C3N4 nanosheet (BCN). The photocatalysts were successfully characterized by various physicochemical techniques and their photocatalytic activities were tested towards the water oxidation reaction to produce oxygen and Cr (VI) reduction under visible light. The HRTEM confirms Ag3PO4 with a particle size of 15 nm has been deposited on BCN to construct a p-n heterojunction. The BCNS-50 absorbs more visible light in the solar spectrum as compared to other catalyst, demonstrating the ability to generate 587 mu mol h(-1)g(-1) O-2 and reduces 98\% of 20 ppm Cr (VI) solution in 1 h. The lower PL intensity as well as lower arc value in case of BCNS-50 suggests the maximum e-h separation and lower charge transfer resistance across the semiconductor/electrolyte interface. The BCN sheet provides a compact heterojunction where the oxidation peak of Ag3PO4 decreases gradually and disappear in case of BCNS-50 suggesting the enhance stability of Ag3PO4 in the heterojunction. BCNS-50 could able to produce -139 and 3087.5 mu A photocurrent both in cathodic and anodic direction which is approximately 7 and 2.4 folds higher as compared to nano Ag3PO4. The generation of photocurrent in both cathodic and anodic direction confirms the formation of p-n heterojunction which further supported by Mott-Schottky analysis. Furthermore the construction of the p-n heterojunction is verified via Mott-Schottky study. DFT calculation explains the contribution of various atomic orbital of Ag3PO4 and BCN towards the formation of hybrid orbital in the heterojunction and the path for charge delocalization between them. This work may provide a limelight and alternative pathway for enhanced photocatalytic performance on construction of the p-n heterojunction in a simple way. (C) 2021 Elsevier B.V. All rights reserved.}, keywords = {Cr (VI) reduction, Density functional theory, Interfacial zone, p-n heterojunction, Photocatalyst, Water oxidation}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2021.162853}, author = {Sahoo, Mitarani and Babu, Pradeepta and Singh, Chandrodai Pratap and Krishnamurty, Sailaja and Parida, Kulamani} } @article {50166, title = {Dynamic and resilient cobalt copper nitride and iron nitride heterostructure aided energy economic urea electrolysis in anion exchange membrane electrolyzer}, journal = {Small}, volume = {22}, year = {2026}, month = {MAY}, type = {Article}, abstract = {

Urea oxidation reaction (UOR) is recognized for energy-efficient hydrogen production, which nonetheless requires a meticulously designed electrocatalyst with active sites for intermediates adsorption and gaseous products desorption to fully exploit its advantages. Herein, we design the heterostructure consisting of cobalt copper nitride and iron nitride (Co3CuN/FexNy) as an efficient and trifunctional electrocatalyst, which requires 1.35 VRHE, 1.55 VRHE, and 0.23 VRHE potentials to reach 100 mA cm-2 current density for UOR, oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), respectively. Unlike the conventional UOR selective electrocatalyst, Co3CuN/FexNy not only facilitates the UOR -\> OER switching but also shows self-regulatory ability in UOR \<-\> OER. The Density Functional Theory (DFT) study explained that while Co3CuN promoted the adsorption of CO(NH2)2 and H2O, FexNy facilitated CO2 and N2 desorption, resulting in accelerated UOR and HER kinetics. The electrocatalyst also demonstrated outstanding performance in a urea-coupled AEM electrolyzer with about 20\% of power saving and great electrolyzer efficiency, further highlighting its potential for industry-relevant applications.

}, keywords = {AEM electrolyzer, heterostructured electrocatalyst, reversible adaptability, urea oxidation, Water oxidation}, issn = {1613-6810}, doi = {10.1002/smll.202600012}, author = {Sinha, Nibedita and Das, Chandni and Er, Chen-Chen and Urkude, Rajashri R. and Pal, Santanu and Ghosh, Biplab and Chai, Siang-Piao and Roy, Poulomi} }