Photoelectrochemical oxidation of amines to imines coupled with <scp> H ₂ </scp> production

Abstract Photoelectrochemical (PEC) oxidation of primary amines to imines offers a sustainable route to nitrogen‐containing compounds, yet achieving efficient and selective conversion under aqueous conditions remains challenging. Herein, we report selective PEC synthesis of imines from amines by using a TiO 2 ‐supported Au nanoparticles (Au/TiO 2 ) photoanode. For the conversion of benzylamine to N‐benzylidenebenzylamine (NBI), the photoanode shows a two‐fold enhancement in NBI productivity (29.5 μmol cm −2 h −1 ) compared to TiO 2 , while maintaining a high selectivity of 94.2%. Additionally, the productivity of H 2 reaches 41.5 μmol cm −2 h −1 over the cathode. Comprehensive mechanistic studies further suggest that the reaction proceeds through two parallel pathways, including electrophilic hydroxyl OH* (major) and lattice oxygen (minor) oxidations. A proof‐of‐concept PEC tandem device produces 3.4 mmol NBI and 125 mL H 2 at 1.0 V for 24 h. This work provides a sustainable PEC route for amines upgrading coupled with H 2 production under mild conditions.