Density functional theory study on the electronic and optical properties of three crystalline phases of BiVO4

The differences in the photocatalytic activity of bismuth vanadate in three crystalline phases have been investigated through calculating their electronic structures and optical properties based on density functional theory. Our results indicate that zircon-tetragonal BiVO4 has a direct and wide band gap, while monoclinic BiVO4 and scheelite-tetragonal BiVO4 has indirect and narrow band gaps. The density of states and atom populations of monoclinic and scheelite-tetragonal phases are similar, but slightly different from those of zircon-tetragonal phase. Among three phases, the monoclinic BiVO4 possesses the largest dipole moment and the lightest effective mass of carriers, which can promote the generation and separation of photo-induced carriers, and subsequently may improve photocatalytic activity.