Efficient visible light-driven photocatalytic CO2 reduction by self-assembled CsPbBr3 perovskite quantum dots on two-dimensional Bi2O2CO3 petals

All-inorganic halide perovskites, such as CsPbBr3 (CPB), face inherent limitations in the photocatalytic reduction of CO2 due to their accelerated radiative recombination and insufficient charge carrier separation. In this work, a heterogeneous photocatalyst comprising Bi2O2CO3 (BOC) petals and CPB quantum dots (QDs) was prepared. The opposite surface potentials of the BOC and CPB QDs enabled their electrostatic self-assembly. The CPB QD/BOC exhibited staggered energy-band configurations with a built-in internal electric field, leading to electron migration from the CPB QD to the BOC petals. Owing to its unique band structure and internal electric field, the CPB QD/BOC exhibited an S-scheme-type heterojunction, resulting in fast charge separation. As a result, the CPB QD/BOC exhibited a significantly enhanced photocatalytic CO2 conversion rate to CO (80.5 μmol g–1 h–1) compared to pristine CPB QD (43 μmol g–1 h–1). This study opens new avenues for designing highly efficient photocatalysts using inorganic halide perovskites.