Glycine‐Functionalized CsPbBr 3 Nanocrystals for Efficient Visible‐Light Photocatalysis of CO 2 Reduction

Capping ligands are indispensable for the preparation of metal‐halide‐perovskite (MHP) nanocrystals (NCs) with good stability; however, the long alkyl‐chain capping ligands in conventional MHP NCs will be unfavorable for CO 2 adsorption and hinder the efficient carrier separation on the surface of MHP NCs, leading to inferior catalytic activity in artificial photosynthesis. Herein, CsPbBr 3 nanocrystals with short‐chain glycine as ligand are constructed through a facile ligand‐exchange strategy. Owing to the reduced hindrance of glycine and the presence of the amine group in glycine, the photogenerated carrier separation and CO 2 uptake capacity are noticeably improved without compromising the stability of the MHP NCs. The CsPbBr 3 nanocrystals with glycine ligands exhibit a significantly increased yield of 27.7 μmol g −1  h −1 for photocatalytic CO 2 ‐to‐CO conversion without any organic sacrificial reagents, which is over five times higher than that of control CsPbBr 3 NCs with conventional long alkyl‐chain capping ligands.