ZnS microsphere/g-C3N4 nanocomposite photo-catalyst with greatly enhanced visible light performance for hydrogen evolution: synthesis and synergistic mechanism study

Abstract

In this work, ZnS microsphere/g-C₃N₄ nanocomposites with different ZnS contents were synthesized by a facile precipitation route and characterized by a variety of techniques. The TEM results confirmed that ZnS microspheres are deposited on the surface of g-C₃N₄ nanosheets with intimate contact in the nanocomposites. Such type-II heterostructures formed between ZnS and g-C₃N₄ can unexpectedly improve the photocatalytic H₂-production rate of g-C₃N₄ under visible light, which reaches an optimal value of up to 194 μmol h⁻¹ g⁻¹ at the ZnS content of 50 wt%. The synergistic effect of ZnS and g-C₃N₄ was proposed to be responsible for the efficient separation of the photogenerated charge carriers and, consequently, the enhancement of the visible light photocatalytic H₂ production activity of the nanocomposites. This work highlights that the integration of g-C₃N₄ and ZnS will be an opportunity to obtain a g-C₃N₄-based nanocomposite photocatalyst with enhanced photocatalytic H₂ production activity, and we hope our work may be helpful for the construction of photocatalysts with efficient visible light H₂-production activities.