Recent progress on the photocatalytic hydrogen evolution reaction over a metal sulfide cocatalyst-mediated carbon nitride system

Under the dual background of energy and environment, the use of precious metal-free carbon nitride (g-C 3 N 4 ) for photocatalytic H 2 evolution has attracted the attention of scientific researchers. Nonetheless, bulk g-C 3 N 4 suffers from serious drawbacks, such as severe photo-generated carrier recombination and scarcity of active sites. Among numerous modification strategies, cocatalyst loading can extract photogenerated charges, provide effective active sites, and reduce reaction activation energy, thus obtaining better catalytic efficiency. Metal sulfides (MSs) are one of the materials that have replaced precious metals as cocatalysts in recent years owing to their unique electronic structure, low cost, and Gibbs free energy close to Pt. As a result, it is imperative to examine the research advancements in the MS/g-C 3 N 4 system. In this paper, the structure and properties of g-C 3 N 4 are reviewed, and the mechanism and role of a cocatalyst binding to g-C 3 N 4 are discussed. Next, typical MS cocatalysts, including their modification strategies and loading techniques, are introduced. Finally, the article discusses the main issues and future research directions for MS/g-C 3 N 4 systems. In conclusion, this review can enhance our comprehension of the correlation between g-C 3 N 4 and cocatalysts, offering more efficient insights for the development of alternative MS cocatalysts. Modification strategy and synthesis method of a metal sulfide-mediated carbon nitride photocatalytic H 2 production system.