▎ 摘　　要

ZnV2O6 modified by graphite is a promising photocatalyst to improve CO2 reduction efficiency. In this paper, the density functional theory studied the energy band structure, charge transfer, and optical properties of graphene/ZnV2O6(001) heterojunction. The mechanism of performance enhancement of graphene/ZnV2O6(001) heterojunction is explored. The results state that the energy band structure of graphene/ZnV2O6(001) is reduced to 0.025eV due to graphene's hybridization. Under visible light irradiation, electrons transition from the top of the ZnV2O6 valence band to the conduction band and are excited to graphene due to the electrostatic field, which promotes electron-hole pairs' separation inhibit the recombination of carriers. The ground state interface electron transfer encourages the increase of surface electrons of graphene and accumulates a large number of holes on ZnV2O6(001). A good combination of ZnV2O6(001) and graphene is beneficial to charge transfer and improve photocatalytic efficiency. The calculated results show that the band structure of graphene/ZnV2O6(001) heterojunction has apparent advantages in improving the visible light photocatalytic efficiency, consistent with the present experimental observation. Besides, our work can also serve as the basis for designing vanadate-based semiconductor heterostructures in photocatalysts and solar cells. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).