Preparation of Bi 2 O 3 /BiOI composite photocatalytic material by solvothermal method and its application to the degradation of tetracycline

As a widely used antibiotic, tetracycline exists in water environment for a long time and is difficult to be degraded naturally, which does great harm to ecological environment and human health. In this article, BiOI and Bi2O3/BiOI photocatalysts were prepared by simple room temperature stirring method and solvothermal method. The morphology and structure of the materials was characterized by XRD, SEM, FT-IR, UV-Vis, PL and EIS. The effects of different preparation conditions on the degradation of tetracycline by Bi2O3/BiOI composite photocatalytic material under simulated sunlight were investigated. The results show that when the molar ratio of Bi2O3 to BiOI is 0.8∶1, the reaction pH is 5, the reaction temperature is 180℃, the reaction time is 20 h, the composite photocatalytic material has the best degradation effect on tetracycline, which can reach 75% in 3 h. And the kinetic rate constants are1.75 times and 1.56 times of that of single BiOI and Bi2O3, respectively. In this study, a catalytic mechanism of binary heterojunction photocatalyst is proposed to explain the improved photocatalytic activity.