Density Functional Theory Study of Electronic Structure and Optical Properties of W-Doped γ-Bi2MoO6

We employed density functional theory (DFT) to investigate the effect of tungsten (W) doping on the crystal structure, electronic properties, and optical response of Bi2MoO6−xWxO6. The results show that W doping retains the Aurivillius orthorhombic lattice structure while inducing localized distortions. All doping systems retain semiconductor characteristics with a band gap ranging from 2.11 to 2.26 eV. The valence band is mainly composed of O-2p orbitals, while the conduction band consists of Mo-4d and W-5d states. As W doping increases, the influence of W-5d states near the conduction band edge intensifies, modulating the electronic structure. Optical calculations show that W doping shifts the absorption edge and allows for precise adjustment of the absorption threshold in the visible light range. These findings provide insight into how W doping affects the electronic and optical properties of γ-Bi2MoO6 and offer a theoretical basis for improving Bi2MoO6-based photocatalytic materials.