Amino Acid-Assisted Preparation of Homogeneous PbS/CsPbBr₃ Nanocomposites for Enhanced Photoelectrocatalytic CO₂ Reduction

As a potential candidate for photocatalytic CO2 reduction, CsPbX3 perovskite nanocrystals (PNCs) have attracted enormous attention due to their suitable energy band structure and large molar extinction coefficient for visible light. However, the catalytic performance on CO2 reduction is greatly limited due to the intrinsically fast radiative recombination and poor stability of PNCs. In this work, PbS nanoparticles are uniformly anchored on CsPbBr3 PNCs with the assistance of a bridged amino acid due to the directed interaction between −COO– (−NH3+) and Pb2+ (Br–). Because of the small lattice mismatch between PbS and CsPbBr3, the introduction of PbS significantly quenches the emission of CsPbBr3 and boosts the interfacial charge transfer, thereby resulting in an enhanced photoelectrocatalytic CO2 reduction rate of ∼2.94 and 0.36 μmol cm–2 h–1 for CO and CH4 products, which are ∼2.4 times higher than that of pristine CsPbBr3 PNCs, respectively. This work provides a universal strategy of constructing homogeneous nanocomposites for catalytic applications.