Abstract:Bi2O3-TiO2/Ti thin film electrodes have been prepared by sol-gel method. The characterization of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and photoelectric performance test demonstrates Bi was successfully doped into TiO2 photocatalyst and it existed in the form of Bi2O3. Compared to pure TiO2 photocatalyst, light response wavelength of Bi2O3 doped TiO2 photocatalyst has been extended and it has obvious photoelectric response in visible region. The dual slant-placed electrodes thin-film reactor was assembled, using the prepared Bi2O3-TiO2/Ti as photoanode and Cu as cathode, and successfully used to photocatalytic (PC) treat Reactive Brilliant Red X-3B (RBR) under visible light irradiation. The main influence factors of the PC reaction were investigated. The decolourization efficiency of 20mg/L RBR reached 88% for 150min treatment under the conditions of initial pH 2.52 and circulating flux 80mL/min. The preliminary mechanism of the dual electrodes thin-film PC was investigated. The results demonstrate the photogenerated electrons can be spontaneously transferred from the surface of the Bi2O3-TiO2/Ti photoanode to the surface of Cu cathode. On the surface of Cu cathode, electrons can reduce RBR directly, or react with dissolved oxygen to form H2O2, which can further participate in the oxidation of the RBR. In this way, dual electrodes degradation can be obtained by the direct oxidation on Bi2O3-TiO2/Ti photoanode and indirect oxidation and direct induction on Cu cathode.