The heterojunction‐type structure has shown significant merits in tuning the optical properties and carrier physics. Inspired by the excellent absorption capability of halide perovskite materials for visible light, a series of CsPbBr₃/TiO₂ heterojunction‐type photocatalysts with various all‐inorganic‐perovskite/TiO₂ ratios are successfully fabricated by the ligand‐assisted reprecipitation (LARP) method. The heterojunction structure extends the light absorption of TiO₂ with good chemical and structural stability. A Pb‐O interaction at the CsPbBr₃/TiO₂ interface is observed by the XPS and confirmed by the TRPL showing improved interface carrier transport and stability. The heterojunction‐type catalyst shows drastically enhanced photocatalytic activity towards the direct oxidation of toluene with O₂ molecule, as an important reaction for organic chemical synthesis. The optimized sample shows an activity of 2356 μmol·g^–1·h^–1 at 75 °C, 4 times of that of the naked CsPbBr₃ nanocrystals, and 3 times of that of the bare TiO₂. Based on the investigation with trapping agents, a reaction mechanism is hence proposed suggesting that the photo‐generated hole may be involved in the rate‐limiting step. This work demonstrates the potential of inorganic halide perovskite‐based heterojunction structure for photocatalytic applications.

中文翻译：

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无机卤化物钙钛矿CsPbBr3的异质结型光催化系统

异质结型结构在调节光学性能和载流子物理特性方面显示出显着优点。受卤化钙钛矿材料对可见光的出色吸收能力的启发，通过配体辅助沉淀法（LARP）成功制备了一系列具有各种全无机钙钛矿/ TiO ₂比的CsPbBr ₃ / TiO ₂异质结型光催化剂。。异质结结构以良好的化学和结构稳定性扩展了TiO ₂的光吸收。CsPbBr ₃ / TiO ₂处的Pb-O相互作用XPS观察到界面并通过TRPL确认，显示出改善的界面载流子传输和稳定性。作为有机化学合成的重要反应，异质结型催化剂对甲苯被O ₂分子直接氧化显示出显着增强的光催化活性。优化后的样品在75°C下的活性为2356μmol·g ^–1 ·h ^–1，是裸露的CsPbBr ₃纳米晶体的4倍，是裸露的TiO _2的3倍。。基于对捕集剂的研究，因此提出了反应机理，表明光生空穴可能参与了限速步骤。这项工作证明了基于无机卤化物钙钛矿的异质结结构在光催化应用中的潜力。