Mechanism of enhancing visible-light photocatalytic activity of BiVO4via hybridization of graphene based on a first-principles study. Issue 8 (16th January 2017)

• Record Type: Journal Article
• Authors: Chen, Yuxuan; Ma, Xinguo; Li, Di; Wang, Huihu; Huang, Chuyun
• Is Part Of: RSC advances. Volume 7:Issue 8(2017)
• Page Start: 4395
• Page End: 4401
• Publication Date: 2017-01-16
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra25721f
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : The interface properties of the hybrid graphene/BiVO4 (001) heterojunction were investigated by first-principle calculations incorporating semiempirical dispersion-correction schemes to describe correctly van der Waals interactions. 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.