Defect engineering of zeolite imidazole framework derived ZnS nanosheets towards enhanced visible light driven photocatalytic hydrogen production

In this work, zeolite imidazole framework-8 (ZIF-8) was employed as a sacrificing template for defect engineering of zinc sulfide (ZnS) photocatalysts to overcome their limited light response and stability. Through controlling the feeding concentration of sulfur source, the tunable density of sulfur vacancy was facially realized and accompanied with the transformation into zinc vacancy. The introduction of vacancy sites created impurity bands, which could promote visible light response and facilitate charge transport/separation. As a result, the as-prepared ZnS materials showed promoted light harvesting in visible region and suppressed electron-hole recombination. Especially, due to the synergistic effect of enhanced visible light harvesting and improved charge carrier kinetics, the ZnS-15 sample with abundant sulfur vacancy sites exhibited enhanced photocatalytic hydrogen production with an average rate up to 741.80 μmol g−1 h-1 under visible light irradiation and negligible photo-induced corrosion in the consecutive catalytic runs.