Photocatalytic CO 2 Reduction Coupled with Oxidation of Benzyl Alcohol over CsPbBr 3 @PANI Nanocomposites

Herein, we successfully prepare conductive polyaniline (PANI)-encapsulated CsPbBr perovskite nanocrystals (PNCs) that demonstrate much improved photocatalytic performance and stability toward the CO reduction reaction (CRR) coupled with oxidation of benzyl alcohol (BA) to benzaldehyde. Due to the acid-base interaction between CO and PANI, CO molecules are selectively adsorbed on PANI in the form of carbamate. As a result, the rate of production of CO ( ) reaches 26.1 μmol g h with a selectivity of 98.1%, which is in good agreement with the rate of oxidation (∼27.0 μmol g h ) of BA. Such a high reduction/oxidation rate is enabled by the fast electron transfer (∼2.2 ps) from PNCs to PANI, as revealed by femtosecond transient absorption spectroscopy. Moreover, because of the benefit of the encapsulation of PANI, no significant decrease in is observed in a 10 h CRR test. This work offers insight into how to simultaneously achieve improved photocatalytic performance and stability of CsPbX PNCs.