Photocatalytic integrated production of hydrogen and imines from aromatic amines via Ni-mesoporous carbon nitride: An acceptorless dehydrogenative pathway

Photocatalysis manifests an invariably quite sustainable process for various chemical transformations. Utilization of electrons and holes for H₂ production and organic transformation boost up the chemical economics for the simultaneous production of H₂ and value-added organic chemicals. This work demonstrated a photocatalytic acceptorless dehydrogenation (PAD) of aromatic amines to imines coupled with H₂ evolution over mesoporous carbon nitride (SGCN) photocatalyst by using non-noble metal (Ni). As synthesized 2 wt% Ni@SGCN catalyst showed superior photocatalytic activity (visible light) for furfuryl amine valorization with H₂ generation rate of 5.03 μmol/h/g along with 12.5% conversion to imine in 6 h. Among all, 4-methoxybenzylamine depicted a high H₂ production rate of 23.58 μmol/h/g along with a maximum 36% conversion in 6 h. Eventually, an experiment under natural sunlight showed an H₂ generation rate of 4.6 μmol/h/g along with 12% conversion of furfuryl amine in 6 h. Moreover, the AQE (%) of the H₂ production was estimated to be 1.1% (400 nm, 20 mg catalyst).