Recent modernization in g-C₃N₄/MoS₂ derived heterojunctions for photocatalytic applications

Photocatalysis using semiconductors is a key approach for directly utilizing, transforming, and storing renewable solar energy and it has important implications for environmental applications. g-C₃N₄ is a prominent semiconductor photocatalyst with advantageous structural, electrical, optical, and chemical properties. However, it suffers from issues like high recombination rates of photogenerated charge carriers, low quantum efficiency, limited surface area and poor light absorption. These limitations can be mitigated by creating heterojunctions with complementary materials. As a transition metal dichalcogenide, MoS₂ is particularly suitable for coupling with g-C₃N₄ because of its compatible band alignment and efficient interfacial charge transfer characteristics which promote charge separation and enhance photoredox activity. This review examines recent advances and applications of the promising g-C₃N₄/MoS₂ heterojunction. The band structures, heterojunction formation and interfacial charge-transfer processes under light irradiation revealed by DFT studies of g-C₃N₄/MoS₂ heterojunctions, are systematically discussed. It critically summarizes advances in diverse design strategies and highlights the importance of constructing hierarchical g-C₃N₄/MoS₂-based heterojunctions integrated with carbonaceous materials, noble metals, metal oxides, polymers, and MOFs to enhance photocatalytic performance. The mechanistic pathways proposed for different heterostructure configurations, including Type-II, Z-scheme and S-scheme systems, are examined in detail with emphasis on their band alignment and charge-transfer characteristics. Subsequently the more exciting photocatalytic applications of g-C₃N₄/MoS₂ based heterojunctions including hydrogen generation, organic and inorganic pollutant degradation, CO₂ reduction and N₂ fixation are addressed in detail. Finally, this comprehensive review concludes with a summary of the key advances and future research directions in g-C₃N₄/MoS₂ based photocatalysts, highlighting emerging research opportunities toward their long-term practical applications.