Self-Assembly of Active Bi₂O₃/TiO₂ Visible Photocatalyst with Ordered Mesoporous Structure and Highly Crystallized Anatase

Abstract

Bi2O3/TiO2 nanocrystallines with ordered mesoporous structure are synthesized by ab evaporation-induced self-assembly method. During liquid-phase photocatalytic degradation of p-chlorophenol under visible illumination (λ > 420 nm), this catalyst exhibits high activity owing to the synergetic effects of both the Bi2O3-photosensitization and the unique structural characteristics. The Bi2O3-photosensitization of TiO2 could extend the spectral response from UV to visible area, making the Bi2O3/TiO2 photocatalyst easily activated by visible lights. The ordered mesoporous channels facilitate the diffusion of reactant molecules. Meanwhile, the high surface area could enhance the Bi2O3 dispersion, the light harvesting, and the reactant adsorption. Furthermore, the highly crystallized anatase may promote the transfer of photoelectrons from bulk to surface and thus inhibit their recombination with photoholes, leading to enhanced quantum efficiency.