First-principles calculations on electronic, optical and photocatalytic properties of BiNbO4

Abstract

This paper has studied the electronic structures, effective masses and photocatalytic properties of BiNbO4 by using the method of density-functional theory (DFT) calculations. Additionally, we investigate the corresponding redox ability through the calculated redox potential. The optical properties involving dielectric function and absorption coefficient are shown and analyzed. The obtained band structures indicate that the α-BiNbO4 has the largest band gap. By comparing the redox potential, we find that BiNbO4 tend to have no reduction ability but strong oxidation capacity. The effective masses and electrons mobility we calculated show the anisotropy in electrons transportation. Moreover, the optical properties indicate that the transparency of α-BiNbO4 is better than that of β-BiNbO4, which leads to a conclusion that α-BiNbO4 is an outstanding semiconductor with excellent transparency and superior oxidation ability in photocatalysis.