The Doping Effect of Bi on TiO₂ for Photocatalytic Hydrogen Generation and Photodecolorization of Rhodamine B

The dependence of photoactivity on Bi doping on TiO 2 was studied for photocatalytic hydrogen generation and rhodamine B (RhB) decolorization. After Bi doping, the hydrogen photogeneration rate increased by a factor of ca. 10, and the decolorization rate for RhB increased two times under visible light radiation (>420 nm). The doping also led to the remarkable photocurrent enhancement. The clear dependence between photocurrent intensity and photoactivity was observed. The optimal dosage of Bi in TiO 2 was about 1.0 mol %. The Bi species existed both in Bi 2 O 3 and Bi 0 forms in TiO 2, and the ratio of Bi 2 O 3 and Bi 0 was dependent on the treatment processes. Results implied that Bi doping increased photoinduced charge separation and resulted in a relatively lower overpotential for H 2 photoevolution.