Construction of Cs2AgBiCl6/COF Heterojunction for Boosted Photocatalytic Thioester Oxidation

Lead‐free halide perovskites as a new kind of potential candidate for photocatalytic organic synthesis have attracted much attention recently. The rational heterojunction construction is regarded as an efficient strategy to delicately regulate their catalytic performances. Herein, a semi‐conductive covalent organic framework (COF) nanosheet, C4N, is employed as the functional component to construct Cs2AgBiCl6/C4N (CABC/C4N) heterojunction. It is found that the C4N nanosheets with rich surface functional groups can serve as heterogeneous nucleation sites to manipulate the growth of CABC nanocrystals and afford close contact between each other, therefore facilitate the transfer and spatial separation of photogenerated charge carriers, as verified by in situ X‐ray photoelectronic spectroscopy and Kelvin probe force microscopy. Moreover, the oxygen affinity of C4N endows the heterojunctions with outstanding aerobic reactivity, thus improving the photocatalytic performance largely. The optimal CABC/C4N heterojunction delivers a thioanisole conversion efficiency of 100% after 6 h, which is 2.2 and 7.7‐fold of that of CABC and C4N. This work provides a new ideal for the design and application of lead‐free perovskite heterojunction photocatalysts for organic reactions. A lead‐free perovskite‐based heterojunction of Cs2AgBiCl6/C4N is designed and constructed for photocatalytic thioester oxidation. The high‐quality heterointerface between Cs2AgBiCl6 and C4N can facilitate the fast transfer and effective separation of photogenerated electron‐hole pairs; moreover, the oxygen affinity of C4N endows the heterojunctions with outstanding aerobic reactivity, thus contributing to largely enhanced photocatalytic performance.