Publications by authors named "Devipriya Gogoi"

3 Publications

  • Page 1 of 1

Step-Scheme Heterojunction between CdS Nanowires and Facet-Selective Assembly of MnO-BiVO for an Efficient Visible-Light-Driven Overall Water Splitting.

ACS Appl Mater Interfaces 2021 Sep 14. Epub 2021 Sep 14.

Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.

The spatial separation and transport of photogenerated charge carriers is crucial in building an efficient photocatalyst for solar energy conversion into chemical energy. A step-scheme CdS/MnO-BiVO photocatalyst was synthesized by spatial deposition of MnO and one-dimensional (1D) CdS nanowires on a three-dimensional (3D) decahedron BiVO surface. The photocatalytic activity of CdS/MnO-BiVO for the overall water-splitting reaction was investigated without sacrificial reagent under visible light irradiation. The synthesized photocatalysts were thoroughly analyzed using high-end characterization techniques. The 5CdS/MnO-BiVO exhibited the highest H and O production rates of 1.01 and 0.51 mmol g h, respectively, with an apparent quantum yield of 11.3% in the absence of any sacrificial reagent. The excellent photoactivity is due to the presence of oxygen vacancies along with effective charge separation/transfer properties and strong interaction of cocatalysts (MnO and Pt) with the photocatalysts (BiVO and CdS) in the 5CdS/MnO-BiVO heterojunction. The significance of the presence of MnO and Pt cocatalysts on the selective facets of BiVO for efficient overall water splitting reaction is highlighted in this work.
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http://dx.doi.org/10.1021/acsami.1c11740DOI Listing
September 2021

Hollow cuboidal MnCoO coupled with nickel phosphate: a promising oxygen evolution reaction electrocatalyst.

Chem Commun (Camb) 2021 Aug;57(65):8027-8030

Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.

The growth of hierarchical morphologies of complex metal oxides directly on the substrate is a challenging task. Herein we report a unique hollow-cuboidal MnCo2O4 (h-MCO) morphology that offers insights into the efficient charge-transfer and surface kinetics for the oxygen evolution reaction. h-MCO coupled nickel phosphate under alkaline conditions outperforms the benchmark RuO2.
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http://dx.doi.org/10.1039/d1cc02383gDOI Listing
August 2021

A Z-Scheme Strategy that Utilizes ZnIn S and Hierarchical VS Microflowers with Improved Charge-Carrier Dynamics for Superior Photoelectrochemical Water Oxidation.

Chem Asian J 2019 Dec 9;14(24):4607-4615. Epub 2019 Jul 9.

Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, 781039, India.

One of the major limiting factors for efficient photoelectrochemical water oxidation is the fast recombination kinetics of photogenerated charge carriers. Herein, we propose a model system that utilizes ZnIn S and hierarchical VS microflowers for efficient charge separation through a Z-scheme pathway, without the need for an electron mediator. An impressive 18-fold increase in photocurrent was observed for ZnIn S -VS compared to ZnIn S alone. The charge-transfer dynamics in the composite were found to follow a Z-scheme pathway, which resulted in decreased charge recombination and greater accumulation of the surface charge. Furthermore, slow kinetics of the surface reaction in the ZnIn S -VS composite correlated to an increased surface-charge capacitance. This feature of the composite material facilitated partial storage of the photogenerated charge carriers (e /h ) under illumination and dark-current conditions, thus storing and utilizing solar energy more efficiently.
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http://dx.doi.org/10.1002/asia.201900545DOI Listing
December 2019
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