Phosphorus Tailors thed‐Band Center of Copper Atomic Sites for Efficient CO2Photoreduction under Visible‐Light Irradiation

Abstract Photoreduction of CO 2 into solar fuels has received great interest, but suffers from low catalytic efficiency and poor selectivity. Herein, two single‐Cu‐atom catalysts with unique Cu configurations in phosphorus‐doped carbon nitride (PCN), namely, Cu 1 N 3 @PCN and Cu 1 P 3 @PCN were fabricated via selective phosphidation, and tested in visible light‐driven CO 2 reduction by H 2 O without sacrificial agents. Cu 1 N 3 @PCN was exclusively active for CO production with a rate of 49.8 μmol CO g cat −1 h −1 , outperforming most polymeric carbon nitride (C 3 N 4 ) based catalysts, while Cu 1 P 3 @PCN preferably yielded H 2 . Experimental and theoretical analysis suggested that doping P in C 3 N 4 by replacing a corner C atom upshifted the d ‐band center of Cu in Cu 1 N 3 @PCN close to the Fermi level, which boosted the adsorption and activation of CO 2 on Cu 1 N 3 , making Cu 1 N 3 @PCN efficiently convert CO 2 to CO. In contrast, Cu 1 P 3 @PCN with a much lower Cu 3d electron energy exhibited negligible CO 2 adsorption, thereby preferring H 2 formation via photocatalytic H 2 O splitting.