Cooperative Syngas Production and C−N Bond Formation in One Photoredox Cycle

Solar‐driven syngas production by CO 2 reduction provides a sustainable strategy to produce renewable feedstocks. However, this promising reaction often suffers from tough CO 2 activation, sluggish oxidative half‐reaction kinetics and undesired by‐products. Herein, we report a function‐oriented strategy of deliberately constructing black phosphorus quantum dots‐ZnIn 2 S 4 (BP/ZIS) heterostructures for solar‐driven CO 2 reduction to syngas, paired with selectively oxidative C−N bond formation, in one redox cycle. The optimal BP/ZIS heterostructure features the enhanced charge‐carrier separation and enriched active sites for cooperatively photocatalytic syngas production with a tunable ratio of CO/H 2 and efficient oxidation of amines to imines with high conversion and selectivity. This prominent catalytic performance arises from the efficient electronic coupling between black phosphorus quantum dots and ZnIn 2 S 4 , as well as the optimized adsorption strength for key reaction intermediates, as supported by both experimental and theoretical investigations. We also demonstrate a synergistic interplay between CO 2 reduction and amine dehydrogenation oxidation, rather than simply collecting these two single half‐reactions in this dual‐functional photoredox system.