Construction of graphene supported dual-phase perovskite quantum dots for efficient photocatalytic CO2 reduction

Lead halide perovskites (LHPs) quantum dots (QDs) has been deemed as a promising material for photocatalytic conversion (e.g., CO2 reduction or water splitting) due to their remarkable photoelectrical properties. However, the severe carrier recombination and low charge transfer efficiency largely restrain their photocatalytic performance. Herein, a series of graphene supported dual-phase perovskite QDs photocatalysts were designed by a facile hot-injection strategy for highly efficient photocatalytic CO2 reduction. Catalytic results showed that under a 5 W white LED irradiation, the CsPbBr3/Cs4PbBr6@G5% composite with 5 wt% graphene loading exhibited an optimum CO yield of 18.76 μmol g−1 with a selectivity of 52.99% towards the product of CO for photocatalytic CO2 reduction. The enhanced photocatalytic CO2 reduction performance over the composites compared with that of CsPbBr3, Cs4PbBr6 and CsPbBr3/Cs4PbBr6 QDs could be ascribed to the type-I heterojunction structure and graphene support as the electron acceptor in the composite, which could stepwise accelerate the charge separation, suppresses recombination process, and provide more active sites for CO2 adsorption and reaction. This work would bring new insight in designing novel efficient perovskite-based catalysts for photocatalytic CO2 transformation.