Structural Stability, Electronic, and Optical Properties of BiVO4 With Oxygen Vacancy Under Pressure.

In this paper, first‐principles calculations are performed to investigate the elastic constants, structural stability, electronic properties, and optical properties of ideal BiVO4 and BiVO4 with oxygen vacancy (Vo‐BiVO4) under equivalent hydrostatic and z‐axial pressure. It is found that the structural stability of the material is not affected and the indirect band‐gap is well kept in BiVO4 and Vo‐BiVO4, independent of the applied pressure. Essentially, as the equivalent hydrostatic and z‐axial pressure is increased, the hybridization of O 2p, V 3d, and Bi 6s orbitals will be enhanced in the ideal BiVO4, while the hybridization of O 2p, V 3d, and Bi 6p orbitals is enhanced in Vo‐BiVO4. Moreover, the band edges are shifted to lower energies under pressure, resulting in substantially reduced band gap, which might facilitate the photocatalytic performance. The shape of the optical spectrum of ideal BiVO4 displays an exponential form while that of Vo‐BiVO4 shows leaf‐like form in the low energy range, although they have similar shapes in the whole energy range. The absorption amount increases with the increase of z‐axial pressure, which might improve the visible light absorption. [ABSTRACT FROM AUTHOR]