Preparation, characterization and photocatalytic activity of polycrystalline Bi2O3/SrTiO3 composite powders

Bi2O3/SrTiO3 composite powders have been prepared and their photocatalytic activities were investigated by photooxidation of methanol. These powders were characterized by UV–Visible diffuse reflectance spectra, SEM and X-ray diffraction (XRD). The results revealed that all the Bi2O3/SrTiO3 composite powders exhibited higher photocatalytic activity than pure SrTiO3, Bi2O3 and TiO2 (P25) under visible light irradiation (λ>440 nm). The effects of the Bi2O3 contents on the photocatalytic activities of the composite powders were examined, the photocatalytic activities increased with the content of Bi2O3 increasing to a maximum of 83% and then decreased under visible light irradiation. The effects of the calcination temperatures on the photocatalytic activities of the composite powders were also investigated.