We report the first-principles electronic structure of BiVO 4, a promising photocatalyst for hydrogen generation. BiVO 4 is found to be a direct band gap semiconductor, despite having band extrema away from the Brillouin zone center. Coupling between Bi 6s and O 2p forces an upward dispersion of the valence band at the zone boundary; however, a direct gap is maintained via coupling between V 3d, O 2p, and Bi 6p, which lowers the conduction band minimum. These interactions result in symmetric hole and electron masses. Implications for the design of ambipolar metal oxides are discussed.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry