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 het-erojunction 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 dras-tically 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 ℃,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 in-volved in the rate-limiting step.This work demonstrates the potential of inorganic halide perovskite-based heterojunction structure for photocatalytic applications.
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