Phosphorus Tailors the d-Band Center of Copper Atomic Sites for Efficient CO Photoreduction under Visible-Light Irradiation.

Photoreduction of CO 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 N @PCN and Cu P @PCN were fabricated via selective phosphidation, and tested in visible light-driven CO reduction by H O without sacrificial agents. Cu N @PCN was exclusively active for CO production with a rate of 49.8 μmol  g  h , outperforming most polymeric carbon nitride (C N ) based catalysts, while Cu P @PCN preferably yielded H . Experimental and theoretical analysis suggested that doping P in C N by replacing a corner C atom upshifted the d-band center of Cu in Cu N @PCN close to the Fermi level, which boosted the adsorption and activation of CO on Cu N , making Cu N @PCN efficiently convert CO to CO. In contrast, Cu P @PCN with a much lower Cu 3d electron energy exhibited negligible CO adsorption, thereby preferring H formation via photocatalytic H O splitting.