Interfacing BiVO4 with Reduced Graphene Oxide for Enhanced Photoactivity: A Tale of Facet Dependence of Electron Shuttling

Hui Ling Tan; Hassan A Tahini; Xiaoming Wen; Roong Jien Wong; Xin Tan; Akihide Iwase; Akihiko Kudo; Rose Amal; Sean C Smith; Yun Hau Ng

doi:10.1002/smll.201601536

Interfacing BiVO₄ with Reduced Graphene Oxide for Enhanced Photoactivity: A Tale of Facet Dependence of Electron Shuttling

Small. 2016 Oct;12(38):5295-5302. doi: 10.1002/smll.201601536. Epub 2016 Jul 21.

Authors

Hui Ling Tan¹, Hassan A Tahini², Xiaoming Wen³, Roong Jien Wong¹, Xin Tan², Akihide Iwase⁴, Akihiko Kudo⁴, Rose Amal⁵, Sean C Smith⁶, Yun Hau Ng⁷

Affiliations

¹ Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
² Integrated Materials Design Centre, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
³ Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia.
⁴ Department of Applied Chemistry, Tokyo University of Science, 1-3 Kagurazaka Shinjuku-ku, Tokyo, 162-8601, Japan.
⁵ Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia. r.amal@unsw.edu.au.
⁶ Integrated Materials Design Centre, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia. sean.smith@unsw.edu.au.
⁷ Particles and Catalysis Research Group, School of Chemical Engineering, The University of New South Wales, Sydney, NSW, 2052, Australia. yh.ng@unsw.edu.au.

PMID: 27442495
DOI: 10.1002/smll.201601536

Abstract

Efficient interfacial charge transfer is essential in graphene-based semiconductors to realize their superior photoactivity. However, little is known about the factors (for example, semiconductor morphology) governing the charge interaction. Here, it is demonstrated that the electron transfer efficacy in reduced graphene oxide-bismuth oxide (RGO/BiVO₄ ) composite is improved as the relative exposure extent of {010}/{110} facets on BiVO₄ increases, indicated by the greater extent of photocurrent enhancement. The dependence of charge transfer ability on the exposure degree of {010} relative to {110} is revealed to arise due to the difference in electronic structures of the graphene/BiVO₄ {010} and graphene/BiVO₄ {110} interfaces, as evidenced by the density functional theory calculations. The former interface is found to be metallic with higher binding energy and smaller Schottky barrier than that of the latter semiconducting interface. The facet-dependent charge interaction elucidated in this study provides new aspect for design of graphene-based semiconductor photocatalyst useful in manifold applications.

Keywords: bismuth vanadate; electron transfer; graphene; photocatalysis; photoelectrochemistry.