A novel co-catalyst system under visible-light irradiation was constructed using high-purity metal and alloy mesh and a Mn0.5Cd0.5S photocatalyst with a narrow band gap (1.91 eV) prepared by hydrothermal synthesis. The hydrogen production rate of Mn0.5Cd0.5S 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.

Developing highly water-stable zeolitic imidazolate frameworks (ZIFs) for visible-light-driven photocatalytic hydrolysis is important and challenging. Herein, the Type II heterojunction catalyst Mn0.5Cd0.5S@ZIF-8 and its derivatives (including MCS@ZIF-8-Mn, MCS@ZIF-8-Br, and MCS@ZIF-8-MB) were successfully constructed using a facile strategy. Through dual postsynthetic ligand and cation exchange (PSE) treatments of Mn(Ac)2·4H2O and 4-bromo-1H-imidazole for ZIF-8, the hydrogen production efficiency of the MCS@ZIF-8-MB heterojunction catalyst can reach 5.450 mmol·g–1·h–1 and remain at 97.11% after 9 h of the stability test. Construction of heterojunctions can effectively improve the hydrogen production performance of Mn0.5Cd0.5S while maintaining excellent water stability. X-ray photoelectron spectroscopy results show that upon successful construction of the MCS@ZIF-8-MB heterojunction an interface forms between the surface of MCS and ZIF-8-MB, effectively weakening the photocorrosion of MCS. Density functional theory calculations also indicate that the induction of Mn can increase the electronic states of p and d orbitals near the Fermi level of ZIF-8, suggesting that Mn(II) attracts more electrons than Zn(II). This provides more powerful theoretical evidence for the electron cloud shift from the electron donor S2– to Mn2+.