Preparation of grape-like Bi2O3/Ti photoanode and its visible light activity

Compact and grape-like bismuth oxide (Bi2O3) coated titania (Ti) anode was prepared by oxalic acid (H2C2O4) etching, electrodeposition and calcination in order to explore its photoelectrocatalytic activities. The Bi2O3 coating was demonstrated to be full of pores, and a good combination between Bi2O3 layer and honeycomb-like Ti substrate was observed by scanning electron microscopy. The characteristic morphology of Bi2O3 coating indicated that the electrode is stable during degradation. The Bi2O3/Ti electrode was used in oxidative degradation of Acid Orange 7 by electrolysis, photocatalytic oxidation and photoelectrocatalytic oxidation processes. The pseudo-first order kinetics parameter (Kapp) of photoelectrocatalytic process was 1.15 times of the sum of electrolysis and photocatalytic oxidation under visible light irradiation at 420 nm. The results indicated that the synergy of electrolysis and photocatalysis lead to an excellent photoelectrocatalytic property of the Bi2O3/Ti electrode.