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

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.