Charge transfer and interfacial binding strategy: Enhancing photocatalytic CO2 reduction efficiency in graphene oxide-modified Cs3BiSbBr9 halide perovskites

Abstract

Meal halide perovskites in standalone configurations face challenges in terms of their fragile stability and charge recombination, which hinders their widespread application in the realm of photocatalysis. In this work, a series of Cs3BiSbBr9/GO (graphene oxide) nanocomposites with different amount of GO nanosheets decorated contents were successfully synthesized and used for CO2 photoreduction performance evaluation. Among them, the photocatalytic performance of Cs3BiSbBr9/GO (10 wt%) increased steadily within 9 h, the CO yield reached 60.71 μmol·g−1·h−1, and the EQE increased over two times. Carrier dynamics studies revealed that the Cs3BiSbBr9/GO (10 wt%) composite enhanced the generation capability of O2− radicals and facilitated the charge transfer from Cs3BiSbBr9 to GO. The surface reaction mechanism confirmed that the photocatalytic CO2 reudction over Cs3BiSbBr9/GO nanocomposite followed the carbonate path, and the oxygen functional group at the edge of GO was conducive to the adsorption and activation of CO2. Our Cs3BiSbBr9/GO photocatalyst is expected to be a promising candidate in the field of CO2 photoreduction.