Preparation of Visible-Light Responsive Photocatalyst (Bi20TiO32) and Its Photocatalytic Activity for Degrading Organic Pollutants

A novel photocatalyst (Bi₂₀TiO₃₂) was synthesized by chemical solution decomposition (CSD) and it was calcined at the temperature of 300°C. It exists in nanosheets with a diameter around 90 nm. The as-prepared Bi₂₀TiO₃₂ is visible-light responsive (up to 500nm in wavelength) without sacrificing its ability for absorbing UV light. The specific activity of Bi₂₀TiO₃₂ is higher than anatase TiO₂ under the same sunlight irradiation condition. It has strong adsorption ability that it can oxidize organics directly by its holes, and it can also degrade organics by ·OH. The photocatalytic mechanism of Bi₂₀TiO₃₂ is the combined effect of both holes and ·OH radicals.