One-step solid-phase synthesis of an efficient heterojunction photocatalyst ZnS/g-C3N4 for H2 production

The relatively low utilization ratio of visible light and fast recombination of photogenerated carriers seriously restrict the photocatalytic capability of g-C₃N₄. In this study, we used Zn (CH₃COO) ₂·2H₂O and thiourea as precursors to successfully construct a stable ZnS/g-C₃N₄ heterojunction photocatalyst through a simple one-step solid-phase method. The results of the UV–vis DRS test show that ZnS/g-C₃N₄ can significantly improve absorption capacity and broaden the absorption range of light, and photoelectrochemical and photoluminescence spectroscopy show that it effectively weakens carrier recombination. The H₂ evolution experiments show that under visible light irradiation, the H₂ generation rate of the 100 ZnS/g-C₃N₄ (100-ZSCN) catalyst is more than 22 times higher than that of bare g-C₃N₄ or ZnS with the same co-catalyst Pt. Based on experimental characterization, density functional theory calculations, and photocatalytic activity tests, we rationalize its photocatalytic hydrogen production mechanism. This study has significant implications for exploiting efficient photocatalysts for H₂ production.