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

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.