Author(s): Tariq, Zeeshan; Rehman, Sajid Ur; Zhang, Xiaoming; Butt, Faheem K.; Feng, Shuai; Ul Haq, Bakhtiar; Cheng, Buwen; Li, Chuanbo

Source: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Volume: 46 Issue: 55 Pages: 28110-28120 Article Number: DOI: 10.1016/j.ijhydene.2021.06.073 Published: AUG 10 2021

Abstract: In the recent past, layered zinc-based vanadium spinel oxides (ZnVOs) have shown an intriguing way to accomplish the challenges of energy conversion, storage, and utilization issues. Here, through first-principles calculations, a comprehensive study has been carried out to investigate the AV(2)M (where A = Zn, Zn-2, Zn-3, Zn-4, and M = O-4, O-6, O-7, O-8, O-9 respectively) electronic, photocatalytic, and optical properties. Formation energies with a negative sign express that the final compounds from the pure elements are possible and cohesive energies revealed that compounds are energetically stable. Spin-polarized calculations are also taken into account for better approximation of the electronic properties (band structure and density of states). All layered structures show indirect bandgap for spin-up calculations in range 0.3 eV-2.4 eV, while spin-down calculations show mix trends in range 2.3 eV-3.50 eV. An appropriate band edge with large enough kinetic over-potentials of the oxygen evolution reaction (DEV > 1.244 eV) makes them potential candidates as photoanode for water splitting. ZnV2O4 is more suitable for OER as it has small kinetic overpotential as compared to the oxidation potential of water. Interestingly, all ZnVOs display a dramatically large coefficient (similar to 10(5) cm(-1)) for optical absorption. Photo-generated electrons and holes on the layered zinc-based vanadium spinel oxide surfaces could make these spinel oxides promising materials for photocatalytic water splitting and solar energy conversion. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Accession Number: WOS:000679244300007

ISSN: 0360-3199

eISSN: 1879-3487

Full Text: https://www.sciencedirect.com/science/article/pii/S0360319921022242?via%3Dihub