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

Abstract

Conversion of CO 2 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 CsPbBr 3 quantum dots (QDs) on the affinal 2D CsPb 2 Br 5 nanosheets for CO 2 photoconversion. CsPbBr 3 QDs were generated by peeling off layers from their cubic counterpart; meanwhile, CsPb 2 Br 5 nanosheets were formed by heaping up the peeled layers. The resultant dual-phase composite exhibited outstanding activity and selectivity for photocatalytic conversion of gaseous CO 2 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 CsPb 2 Br 5 or CsPbBr 3 . Importantly, the fabricated dual-phase material presented extremely high stability and was able to maintain an unchangeable CO 2 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 CsPbBr 3 QDs to transfer rapidly to CsPb 2 Br 5 , and the affluent active sites in such an architecture enabled achieving enhanced CO 2 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 CO 2 conversion.

Highly stable halide perovskites for photocatalysis via multi-dimensional structure design and in situ phase transition

“…The absorbance edge at approximately 380 nm belongs to our newly formed tetragonal CsPb 2 Br 5 NSs, which is consistent with other studies. 43–45…”

“…46 The tetragonal CsPb 2 Br 5 can compensate for the surficial dangling bonds with enriched Pb 2+ and Br − to improve the structural stability. 43…”

“…46 The tetragonal CsPb 2 Br 5 can compensate for the surficial dangling bonds with enriched Pb 2+ and Br − to improve the structural stability. 43 As shown in Fig. S19, † the characteristic peaks of tetragonal CsPb 2 Br 5 can be observed in the XRD pattern of 0.5 PEABr (after the reaction).…”

“…Paper absorbance edge at approximately 380 nm belongs to our newly formed tetragonal CsPb 2 Br 5 NSs, which is consistent with other studies. [43][44][45] The bandgap of QDs in our work (Fig. S16 †) is 2.32 eV, which was obtained by Tauc plots based on the Abs spectrum.…”

“…According to Ding's work, cubic CsPbBr 3 QDs can form Z-scheme-type heterojunctions with tetragonal CsPb 2 Br 5 NSs. 43 Hence, the 0.3 PEABr sample (after the reaction) was investigated further. The absorption spectrum of the 0.3 PEABr sample (after the reaction) (Fig.…”