Mechanism of enhancing visible-light photocatalytic activity of BiVO4 via hybridization of graphene based on a first-principles study

Yuxuan Chen; Xinguo Ma; Di Li; Huihu Wang; Chuyun Huang

doi:10.1039/C6RA25721F

Mechanism of enhancing visible-light photocatalytic activity of BiVO₄via hybridization of graphene based on a first-principles study

Yuxuan Chen,^a Xinguo Ma,*^ab Di Li,^c Huihu Wang^b and Chuyun Huang*^ab

Author affiliations

* Corresponding authors

^a School of Science, Hubei University of Technology, Wuhan 430068, China
E-mail: maxg2013@sohu.com

^b Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy, Hubei University of Technology, Wuhan 430068, China
E-mail: chuyunh@163.com

^c School of Metallurgical Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China

Abstract

The interface properties of the hybrid graphene/BiVO₄(001) heterojunction were investigated by first-principle calculations incorporating semiempirical dispersion-correction schemes to correctly describe van der Waals interactions. The results indicate that graphene and BiVO₄ are in contact and form a stable heterojunction. After equilibration of the graphene/BiVO₄ interface, their energy levels are adjusted with the shift of their Fermi levels based on calculated work functions. In addition, electrons in the upper valence band of BiVO₄ can be excited to the conduction band under irradiation, and then arrive at the C p_z orbital of graphene, in which the electrons cannot migrate back to BiVO₄ and thus are trapped in graphene. Thus, substantial holes are accumulated in the BiVO₄(001) surface, facilitating the separation of photogenerated e⁻/h⁺ pairs. The calculated charge density difference unravels that the charge redistribution drives the interlayer charge transfer from graphene to the BiVO₄(001) surface. It is identified that the hybridization between the two components induces an increase of optical absorption of BiVO₄ in the visible-light region. A deep understanding of the microcosmic mechanisms of interface interaction and charge transfer in this system would be helpful for fabricating BiVO₄-based heterojunction photocatalysts.

Article information

https://doi.org/10.1039/C6RA25721F

Article type

Paper

Submitted

24 Oct 2016

Accepted

11 Dec 2016

First published

12 Dec 2016

This article is Open Access

Download Citation

RSC Adv., 2017,7, 4395-4401

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Mechanism of enhancing visible-light photocatalytic activity of BiVO₄ via hybridization of graphene based on a first-principles study

Y. Chen, X. Ma, D. Li, H. Wang and C. Huang, RSC Adv., 2017, 7, 4395 DOI: 10.1039/C6RA25721F

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