Covalent-bond-enhanced photocatalytic hydrogen evolution of C3N4/CoPx with L-cysteine molecule as bridging ligands

Serious interface carrier recombination leads to moderated photocatalytic performance of carbon nitride (C 3 N 4 ), and the realization of their strongly covalent bonding with co-catalysts can efficiently inhibit this. In this article, C 3 N 4 nanosheets are first functionalized with L-cysteine molecules to form C-SH bonds, and then the photodeposited CoP x NPs are covalently bonded with C 3 N 4 with L-cysteine molecules as bridging ligands, which can efficiently reduce the C 3 N 4 /CoP x interface impedance. Their optimal hydrogen evolution rate and apparent quantum efficiency at 420 nm are 4.12 mmolg −1 h −1 and 3.74%, respectively, which are 17.2 and 13.9 times that C 3 N 4 /CoP x reference without L-cysteine bridging ligands, mainly due to the reduced C 3 N 4 /CoP x interface impedance. This work proposes a general solution to inhibit interface carrier recombination in nanocomposites by introduction of bridging ligands.