Squaric Acid Templated an Organolead Bromide Coordination Polymer with Visible Light Response for Photocatalytic CO2 Reduction

Organolead halide coordination polymers have emerged as promising photocatalysts owing to their attractive photophysical properties and structural tunability. However, organolead bromides typically exhibit limited photocatalytic performance due to their generally narrow light absorption range and inefficient carrier mobility. To overcome these issues, we designed and synthesized a robust layered organolead bromide coordination polymer templated by the squaric acid ligand featuring short carbon chains and broad near-UV absorption. It achieves visible light absorption and high charge separation efficiency, in contrast to the two reported lead bromide analogues with large interlayer spacing. Upon exposure to AM 1.5G simulated sunlight, the hybrid bromoplumbate exhibits enhanced photocatalytic activity for CO2–CO conversion, with high product selectivity and cycling stability. Moreover, the photocatalytic CO2 reduction performance is further promoted by in situ incorporation of trace Ag nanocrystals as reductive cocatalysts for suppressing carrier recombination, prolonging charge lifetime, and reducing free energy for the *COOH key intermediate. This work underscores the critical role of coordination chemistry in modulating the relationship between the structure and property of crystalline materials.