High-density atomic Ag–N frustrated Lewis pair sites for photocatalytic amine oxidation and hydrogen evolution

Photocatalytic amine oxidation coupled with hydrogen evolution offers a sustainable route to green hydrogen and value-added chemicals, yet efficient N–H bond activation remains challenging. Herein, we construct atomic Ag–N frustrated Lewis pairs (FLPs) composed of low-valence Ag single atoms as Lewis acids and adjacent electron-rich N atoms as Lewis bases by anchoring high-density Ag single atoms onto N-deficient g-C 3 N 4 nanosheets to form an Ag–N 1 C 2 structure. These atomic Ag–N FLP sites enable efficient adsorption and selective N–H bond cleavage through synergistic coordination of Ag with the amine N atom and neighboring N sites with H. Meanwhile, Ag single atoms serve as effective hole-transfer bridges, enhancing surface hole accumulation and accelerating oxidation kinetics. The resulting photocatalyst exhibits a benzylamine oxidation rate of 0.85 mmol g cat −1 h −1 , converts benzylamine to N -benzylidenebenzylamine with >99% selectivity, and achieves a hydrogen evolution rate of 1.86 mmol g cat −1 h −1 .