Cs2CuBr4 photocatalyst capable of efficiently adsorbing and reducing CO2

The invention discloses a Cs2CuBr4 photocatalyst capable of efficiently adsorbing and reducing CO2 as well as a preparation method and application of the Cs2CuBr4 photocatalyst. The preparation method comprises the following steps: step 1, adding CsBr and CuBr2 into DMSO (Dimethylsulfoxide), uniformly dispersing the CsBr and the CuBr2, and injecting the solution into isopropanol to obtain a Cs2CuBr4 nanocrystal solution; step 2, adding a molecular sieve into the Cs2CuBr4 nanocrystal solution, and stirring overnight to obtain a suspension; and step 3, centrifuging the suspension obtained in the step 2, and drying the obtained precipitate to obtain the Cs2CuBr4 photocatalyst capable of efficiently adsorbing and reducing CO2, the Cs2CuBr4 photocatalyst has very high CO2 adsorption capacity and catalytic activity, and the stability of Cs2CuBr4 nanocrystals is retained. The preparation method is simple and high in controllability, and large-scale production is easy to realize. 本发明公开一种高效吸附和还原CO2的Cs2CuBr4光催化剂、制备方法及其