Efficient Visible-Light-Driven Photocatalytic Degradation with Bi<sub>2</sub>O<sub>3</sub> Coupling Silica Doped TiO<sub>2</sub>
A new TiO2-based visible light photocatalyst (Bi2O3/Si–TiO2) was synthesized by both Bi2O3 coupling and Si doping via a two-step method. The structural, morphological, light absorption, and photocatalytic properties of as-prepared samples were studied using various spectroscopic and analytical techniques. The results showed that Bi2O3/Si–TiO2 catalysts held an anatase phase and possessed high thermal stability. The doped Si was woven into the lattice of TiO2, and its content had a significant effect on the surface area and the crystal size of Bi2O3/Si–TiO2. The introduced Bi species mainly existed as oxides on the surface of TiO2 particles, and the Bi2O3 photosensitization extended the light absorption into the visible region. Bi2O3 coupling also favored the separation and transfer of photoinduced charge carriers to inhibit their recombination and Si doping enlarged the surface area of photocatalysts. Compared to bare TiO2, Bi2O3/TiO2, and Si–TiO2, Bi2O3/Si–TiO2 samples showed better activities for the de...