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 (• ${O_2}^{-}$) 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.

金属卤化物钙钛矿在水中稳定性差是制约其实际应用的主要障碍之一。采用溶剂热法通过以下烧结工艺合成了水稳定的铯溴化铅-二氧化钛异质结，并应用于可见光驱动的盐酸四环素（TC-HCl）在水中的光降解。引入的TiO ₂组分有效地保护了CsPbBr ₃纳米粒子免于相变，从而显着提高了CsPbBr ₃ -TiO ₂异质结在水中的光催化性能和稳定性。合成的CsPbBr ₃ -TiO₂光催化剂通过XRD 、SEM和TEM进行表征。通过光电化学和光致发光分析研究制备的光催化剂的光电特性表明，增强的光催化性能可能与优化的光响应和异质结复合材料上的电子-空穴分离有关。通过捕获实验确定了光催化过程中的活性物质，表明空穴（h ⁺）和超氧自由基（•${{○}_2}^{-}$) 负责光催化活性。最后提出了反应机理。这项工作为构建耐水卤化物钙钛矿提供了一种替代方案，以突破水稳定性差的问题，并为卤化物钙钛矿基材料在水环境控制中开辟了新的应用。