Design Synthesis And Photocatalytic Performance Study Of Halide Perovskite-based Composite Materials

Halide perovskite materials have broad applications in optoelectronics and are also promising in photocatalysis,among which CsPbBr₃ is a relatively stable halide perovskite material.In this paper,a series of experimental explorations have been carried out centered on the synthesis design and photocatalytic performance research of CsPbBr₃ and its composite materials.Aiming at environmental stability and photogenerated carrier recombination of CsPbBr₃,CsPbBr₃/CdS and g-C₃N₄/Ti O_x/CsPbBr₃ composite materials were constructed to investigate the photocatalysis application of CsPbBr₃.Types of characterization methods were used to analyze material composition,crystal structure,microscopic morphology,band structure and photogenerated carrier separation property.The photocatalytic mechanism was studied by the tests before and the photocatalytic performance.The main contents are as follows:The CsPbBr₃/CdS composite photocatalyst with a solid solution-like structure was synthesized by a modified thermal injection method.The appearance of CdS in the synthesis process promoted the stability and growth of CsPbBr₃ grains.In the photocatalytic CO₂ reduction test,the CO yield of CsPbBr₃/CdS was improved and the reaction stability was better.In the four-hour reaction cycle,the CO yield of the composite photocatalysts were 23.37 and 18.74μmol·g^-1,respectively,and the cumulative CO yields were 1.7 and 1.3 times higher than that of pristine CsPbBr₃,respectively.Combined with the characterization test,it was concluded that CdS was uniformly distributed in the CsPbBr₃ matrix of the orthorhombic crystal.The presence of CdS effectively improved the photoresponse ability and the migration ability of photogenerated carriers of CsPbBr₃,reduced the fluorescence recombination of the CsPbBr₃ matrix,and stabilized the structure of CsPbBr₃,which was beneficial to the improvement of photocatalytic performance.The g-C₃N₄-based composite photocatalysts sensitized by Ti O_x-capped-CsPbBr₃ were prepared by a simple ultrasonic composite method,and the photocatalytic performance was studied by controlling the content of CsPbBr₃.The composite photocatalysts with different CsPbBr₃ contents showed enhanced degradation efficiency,among which the degradation efficiency of tetracycline hydrochloride for the best one reached 68%,and its degradation efficiency was 1.78 times that of the original g-C₃N₄.Combined with the characterization test,it was concluded that the incorporation of CsPbBr₃ greatly improved the photoresponse range and light absorption capacity of the photocatalyst,and the presence of Ti O_xstabilized the structure of CsPbBr₃ and promoted the migration of photogenerated carriers between CsPbBr₃ and the g-C₃N₄ matrix.This paper includes 34 figures,4 tables and 171 references.