Boosting photocatalytic hydrogen generation by the combination of tunable cobaloxime and covalent organic framework

Abstract

Here, we have investigated the photocatalytic activities of substituted Schiff-based COFs as photosensitizes and molecular cobaloximes as non-noble metal co-catalysts for the hydrogen production from water under visible light irradiation. The steric and electronic properties of the functional group at the backbone of COFs, and cobaloximes, have a pronounced effect on the photocatalytic performance of the photocatalytic system. We established that the methyl-substituted COF (COF-AD1) as a photosensitizer, chloro (p-N,N-dimethylpyridine) cobaloxime (Co-2) as co-catalyst and triethanolamine (TEOA) sacrificial electron donor form a highly active photocatalytic system which exhibited a record hydrogen production rate of 7072 μmolg−1h−1 with a quantum efficiency of 51.4%, TOF of 35.6, TON of 462.4 for 20 h in a 4:1 acetonitrile/water mixture.