Preparation and photocatalytic performance of ZnO/ZnGa2O4 composite microspheres

ZnO/ZnGa2O4 composite microspheres with heterojunction were successfully synthesized by one-pot hydrothermal method. These samples were characterized by TG/DTA, XRD, TEM, HRTEM, UV-vis DRS, FL and BET techniques. The results indicated the as-prepared samples showed better degree of crystalline and large specific surface area. The photocatalytic activity was evaluated by degradation of methyl orange with the concentration of 50 mg/L under the irradiation of simulated sunlight. The effects of molar ratio of Zn to Ga and calcination temperature on the photocatalytic activity were investigated in detail. The results showed that the highest photocatalytic degradation efficiency was observed at the molar ratio of Zn to Ga of 1:0.5 in the starting materials and the calcination temperature of 400 degrees C. The maximum photocatalytic degradation rate of MO was 97.1% within 60 min under the simulated sunlight irradiation, which is greatly higher than that of ZnO and ZnGa2O4.