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., CO 2 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 CO 2 reduction. Catalytic results showed that under a 5 W white LED irradiation, the CsPbBr 3 /Cs 4 PbBr 6 @G 5% 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 CO 2 reduction. The enhanced photocatalytic CO 2 reduction performance over the composites compared with that of CsPbBr 3 , Cs 4 PbBr 6 and CsPbBr 3 /Cs 4 PbBr 6 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 CO 2 adsorption and reaction. This work would bring new insight in designing novel efficient perovskite-based catalysts for photocatalytic CO 2 transformation.