Boosting photocatalytic hydrogen evolution of g-C3N4 via enhancing its interfacial redox activity and charge separation with Mo-doped CoSx

To achieve low-cost photocatalytic hydrogen (H2) production, it is necessary to develop low-priced transition metal co-catalysts to replace the roles of noble metals for photocatalytic H2 evolution. Herein, a co-catalyst of Mo-doped CoSx (Mo-CoSx) was synthesized by using the hydrothermal procedure, then attached to g-C3N4 to construct a composite photocatalyst. As a co-catalyst, Mo-CoSx can work as an electron acceptor, it is utilized to receive electrons generated by g-C3N4 photocatalyst on the surface of the catalyst, and inhibit the recombination of those electrons, thus showing enhanced charge transfer ability as well as reduction ability. The optimized Mo-CoSx/g-C3N4 delivered a prominent photocatalytic H2 evolution rate of 2062.4 μmol h−1 g−1, which was ∼193 times higher than g-C3N4. Its AQE at 400 nm and 420 nm were 11.05% and 6.83%, respectively. This work provides a novel non-precious metal co-catalyst/g-C3N4 photocatalyst that is expected to be an acceptable cost route to solar energy conversion.