Metal Mesh and Narrow Band Gap Mn_0.5Cd_0.5S Photocatalyst Cooperation for Efficient Hydrogen Production

A novel co-catalyst system under visible-light irradiation was constructed using high-purity metal and alloy mesh and a Mn_0.5Cd_0.5S photocatalyst with a narrow band gap (1.91 eV) prepared by hydrothermal synthesis. The hydrogen production rate of Mn_0.5Cd_0.5S changed from 2.21 to 6.63 mmol·(g·h)^-1 with the amount of thioacetamide, which was used as the sulphur source. The introduction of Ag, Mo, Ni, Cu, and Cu-Ni alloy meshes efficiently improved the H₂ production rate of the co-catalyst system, especially for the Ni mesh. The improvement can reach an approximately six times greater production, with the highest H₂ production rate being 37.65 mmol·(g·h)^-1. The results showed that some bulk non-noble metal meshes can act as good or better than some noble metal nanoparticles deposited on the main photocatalyst for H₂ evolution due to the promotion of photoinduced electron transfer, increase in redox reaction sites, and prevention of the recombination of carriers.