In situ growth of CsPbBr3 quantum dots in mesoporous SnO2 frameworks as an efficient CO2-reduction photocatalyst

Perovskite CsPbBr3 quantum dots (QDs) have shown great promise in photocatalytic applications but their performance is still largely restricted by severe charge recombination, weak stability, and poor CO2 capturing ability. Herein, CsPbBr3 QDs were grown in situ into mesoporous SnO2 frameworks and a unique CsPbBr3 @SnO2 heterostructure with enhanced CO2-reduction activity and stability was designed. The experimental results and theoretical calculations indicated that the electrons in the CsPbBr3 @SnO2 heterostructure transferred in an S -scheme mechanism, which greatly promoted the charge transfer between CsPbBr3 and SnO2. Besides, the unique porous structure of SnO2 facilitated the CO2 adsorption on the surface of the CsPbBr3 @SnO2 heterostructure. Benefitting from these synergistic effects, the developed CsPbBr3 @SnO2 heterostructure behaved remarkable activity toward CO2 reduction, which was about 3.12-fold higher than pristine CsPbBr3 QDs. This study provides a new pathway to design perovskite-based heterojunction photocatalysts for highly efficient CO2 conversion.