The study on the geometry and electronic properties of (WO3)x/(TiO2)y heterostructure by using the layered structural model

The layered structural model was proposed to study the geometry and electronic properties of the (WO3)(x)/(TiO2)(y) heterostructures in this paper. The geometry and electronic properties were affected greatly by the relative proportion of TiO2 and WO3 in the nanocomposites. The minimum band gap of (WO3)(x)/(TiO2)(y) heterostructures decreased with the proportion of WO3 increasing but increased with the proportion of TiO2 increasing. Interestingly, electrons at the upper valence band (VB) can be directly excited from 2p and 3d orbitals of titania to the conduction band (CB), which was mainly consisted of 5d orbitals of tungsten trioxide. The effective electron mass of (WO3)(x)/(TiO2)(y) heterostructures was higher than that of pure TiO2. It indicated that the electron-hole recombination rate of hybrid (WO3)(x)/(TiO2)(y) heterostructure was lower than that of pure TiO2, which might imply that photocatalytic activities of the hybrid (WO3)(x)/(TiO2)(y) heterostructures were enhanced under visible light irradiation. The theoretical results might offer a new useful guide for designing semiconductors photocatalyst, such as heterostructure nanocomposites.