Modulation of active center distance of hybrid perovskite for boosting photocatalytic reduction of carbon dioxide to ethylene.

Solar-driven photocatalytic CO 2 reduction is an energy-efficient and sustainable strategy to mitigate CO 2 levels in the atmosphere. However, efficient and selective conversion of CO 2 into multi-carbon products, like C 2 H 4 , remains a great challenge due to slow multi-electron-proton transfer and sluggish C-C coupling. Herein, a two-dimensional thin-layered hybrid perovskite is fabricated through filling of oxygen into iodine vacancy in pristine DMASnI 3 (DMA = dimethylammonium). The rational-designed DMASnI 3 (O) induces shrinkage of active sites distance and facilitates dimerization of C-C coupling of intermediates. Upon simulated solar irradiation, the DMASnI 3 (O) photocatalyst achieves a high selectivity of 74.5%, corresponding to an impressive electron selectivity of 94.6%, for CO 2 to C 2 H 4 conversion and an effective C 2 H 4 yield of 11.2 μmol g -1 h -1 . In addition, the DMASnI 3 (O) inherits excellent water stability and implements long-term photocatalytic CO 2 reduction to C 2 H 4 in a water medium. This work establishes a unique paradigm to convert CO 2 to C 2+ hydrocarbons in a perovskite-based photocatalytic system.