Construction of hydrostable cesium lead bromide-titania for visible-light degradation of tetracycline hydrochloride in water

The poor stability of metal halide perovskite in water is one of the main obstacles restricting its practical application. Hydrostable cesium lead bromide-titania heterojunction was synthesized by the solvothermal method with the following sintering process and applied for the visible-light-driven photodegradation of tetracycline hydrochloride (TC-HCl) in water. The introduced TiO2 components effectively protect CsPbBr3 nanoparticles from phase transition which spurs significantly improved photocatalytic performance and stability on CsPbBr3–TiO2 heterojunction in water. The structure of synthesized CsPbBr3–TiO2 photocatalyst is characterized by XRD, SEM, and TEM. The photoelectric characteristics of prepared photocatalysts investigated through photoelectrochemical and photoluminescent analyses indicate that the enhanced photocatalytic property may be related to the optimized light response and electron-hole separation on heterojunction composites. The active substances in the photocatalytic process are determined through capture experiments, indicating that holes (h+) and superoxide radicals (• O2−) are responsible for photocatalytic activity. A reaction mechanism is suggested in the end. This work provides an alternative for the construction of water-resistant halide perovskite to break through the poor water stability and opens novel applications for halide perovskite-based materials in aqueous environmental control.