Synergistic construction of g-C3N4/MoS2/rGO ternary nanocomposite for enhanced photocatalytic degradation under visible light

Graphite carbon nitride (g-C₃N₄) has emerged as a promising photocatalyst for visible-light-driven applications due to its suitable band structure. However, the rapid recombination of photogenerated electron-hole pairs in bulk g-C₃N₄ significantly hinders its photocatalytic efficiency. In this study, we report the fabrication of a ternary g-C₃N₄/MoS₂/rGO (CMG) nanocomposite via in situ photoreduction-induced exfoliation. The introduction of MoS₂ and rGO not only facilitates the exfoliation of g-C₃N₄ into ultrathin nanosheet, thereby exposing more active sites, but also enables the formation of tightly coupled heterojunctions that promote charge separation and transfer. Photoluminescence (PL) analyses confirm the suppressed recombination of charge carriers, indicative of enhanced charge dynamics within the heterojunction between MoS₂, rGO and g-C₃N₄. Among the synthesized materials, the optimized CMG-175 composite exhibits remarkable photocatalytic activity, achieving a 95.7% degradation rate of Rhodamine B (RhB) within 30 min under visible light irradiation, which is 23.6-fold enhancement compared to pristine g-C₃N₄. Mechanistic studies reveal that photogenerated holes and superoxide radicals are the predominant reactive species driving the degradation process. This work highlights a rational design strategy for constructing high-performance g-C₃N₄-based heterojunction photocatalysts and provides valuable insight into the synergistic interactions among MoS₂, rGO, and g-C₃N₄ for efficient organic pollutant removal.