Assembling an Affinal 0D CsPbBr₃/2D CsPb₂Br₅ Architecture by Synchronously In Situ Growing CsPbBr₃ QDs and CsPb₂Br₅ Nanosheets: Enhanced Activity and Reusability for Photocatalytic CO₂ Reduction

Conversion of CO2 into valuable chemical feedstocks through artificial photosynthesis is an effective strategy to alleviate energy and environmental issues. Herein, we have developed a novel perovskite-based catalyst via in situ growing CsPbBr3 quantum dots (QDs) on the affinal 2D CsPb2Br5 nanosheets for CO2 photoconversion. CsPbBr3 QDs were generated by peeling off layers from their cubic counterpart; meanwhile, CsPb2Br5 nanosheets were formed by heaping up the peeled layers. The resultant dual-phase composite exhibited outstanding activity and selectivity for photocatalytic conversion of gaseous CO2 with a CO generation rate of 197.11 μmol g–1 h–1 under 300 W Xe lamp irradiation, which is 2.5 and 1.1 times higher than that of pure CsPb2Br5 or CsPbBr3. Importantly, the fabricated dual-phase material presented extremely high stability and was able to maintain an unchangeable CO2 conversion rate under wet air in the consecutive 10 h of recycling test. Furthermore, attributing to the in situ assembling strategy, the close contact allowed photo-generated electrons in CsPbBr3 QDs to transfer rapidly to CsPb2Br5, and the affluent active sites in such an architecture enabled achieving enhanced CO2 photoconversion activity. The present work provides an attractive approach for in situ constructing a consubstantial perovskite-based composite photocatalyst to ensure great stability and excellent activity for artificial photocatalytic CO2 conversion.