Photo‐Driven Ammonia Synthesis via a Proton‐Mediated Photoelectrochemical Device

Abstract N 2 reduction reaction (NRR) by light is an energy‐saving and sustainable ammonia (NH 3 ) synthesis technology. However, it faces significant challenges, including high energy barriers of N 2 activation and unclear catalytic active sites. Herein, we propose a strategy of photo‐driven ammonia synthesis via a proton‐mediated photoelectrochemical device. We used redox‐catalysis covalent organic framework (COF), with a redox site (−C=O) for H + reversible storage and a catalytic site (porphyrin Au) for NRR. In the proton‐mediated photoelectrochemical device, the COF can successfully store e − and H + generated by hydrogen oxidation reaction, forming COF−H. Then, these stored e − and H + can be used for photo‐driven NRR (108.97 umol g −1 ) under low proton concentration promoted by the H‐bond network formed between −OH in COF−H and N 2 on Au, which enabled N 2 hydrogenation and NH 3 production, establishing basis for advancing artificial photosynthesis and enhancing ammonia synthesis technology.