Precise control of the energy level of conduction band of bismuth vanadate BiVO4 via element doping at the vanadium site

Abstract

In this study, BiV_1-xM_xO₄ (M = Sc, Ti, W, Mo; x = 0, 0.005, 0.01, 0.02, 0.03, 0.05, 0.07, 0.10) samples with monoclinic structure were successfully synthesized by the conventional solid state reaction method, and the doping effects on the crystal structure, band structure and optical properties were investigated. XRD and Rietveld refinement results suggested the formation of solid solutions with monoclinic structure in low concentration range. UV–vis diffuse reflectance, XPS and VBXPS results revealed that the band structure of BiVO₄ could be adjusted by doping elements with different electronegativities into V site. It is found that the energy level of CBM raised by doping Sc and Ti which have lower electronegativities than V, and the energy level of CBM decreased by doping W and Mo which have higher electronegativities than V.