Anchoring Ag Atom on Carbon Vacancy Enriched Carbon Nitride to Synergistically Promote CO₂ Photoredution with Water

Abstract Pristine carbon nitride (CN) has low CO₂ reduction ability due to its sluggish charge carriers transfer and CO₂ activation. Herein, carbon vacancy (CV) and Ag single atoms (SAs) with N2 coordination are simultaneously introduced into CN with the ordered structure for stable and efficient photoreduction of CO₂ in the presence of H₂O. The optimal sample loaded with 0.053 wt.% Ag evolve 173.0 µmol g⁻¹ CO in 3 h with 89% selectivity, which is 11.7 times higher than that of pristine CN (14.7 µmol g⁻¹). Experiments and theoretical calculations reveal that the CV and Ag–N2 sites promote CO₂ adsorption/activation and the generation of ^*COOH and ^*CO. KSCN‐assisted calcination induces more ordered arrangement of melon chains, which can accelerate charge transfer/separation and facilitate H₂O oxidation, thus accounting for the largely improved CO₂ photoreduction performance. This study adopts a new method to prepare Ag SA‐anchored and C‐deficient CN, and provides insights into their synergistic roles in enhancing CO₂ reduction.