P and Cu Dual Sites on Graphitic Carbon Nitride for Photocatalytic CO2 Reduction to Hydrocarbon Fuels with High C2H6 Evolution

摘要

The light-driven CO2 reduction to multi-carbon products is especially meaningful, while the low efficiency of multi-electron transfer and sluggish C-C coupling greatly hinder its development. Herein, we report a photocatalyst comprising of P and Cu dual sites anchored on graphitic carbon nitride (P/Cu SAs@CN), which achieves a high C2H6 evolution rate of 616.6 μmol g~(-1) h~(-1) in reducing CO2 to hydrocarbons. The detailed spectroscopic characterizations identify the formation of charge-enriched Cu sites, where the isolated P atoms serve as hole capture sites during photocatalysis. Theoretical simulations combined with in situ FTIR measurement reveal a kinetically feasible process for the formation of C-C coupling intermediate (~3OC-COH) and confirm the favorable production of C2H6 on the P/Cu SAs@CN photocatalyst. This work offers new insights into the photocatalyst design with atomic precision toward highly efficient photocatalytic CO2 conversion to high value-added carbon products.