Construction of a g-C3N4/MnIn2S4 heterostructure with enhanced carrier separation for efficient photocatalytic degradation performance

This study investigated the controllable synthesis method and photocatalytic performance of a g-C 3 N 4 /MnIn 2 S 4 heterostructure. Through a carefully designed experimental scheme, the g-C 3 N 4 /MnIn 2 S 4 heterostructure was successfully prepared, and its composition, structure, and morphology were thoroughly characterized. The experimental results demonstrated that the heterostructure achieved a high photodegradation efficiency of 92.3% for RhB and 72.8% for TC under visible light, significantly outperforming its individual components. After four cycles, the degradation rate remained relatively stable. The photocatalytic reaction mechanism was thoroughly investigated by adding different trapping agents, revealing that the active species were mainly ·O₂⁻ and h⁺ and EPR, which significantly affected the degradation efficiency. The g-C 3 N 4 /MnIn 2 S 4 heterostructure achieved efficient separation of the photogenerated carriers, significantly enhancing its photocatalytic performance for RhB and tetracycline degradation. VB-XPS tests exhibited that the valence bands of MnIn 2 S 4 and g-C 3 N 4 were 1.25 and 2.25   eV, respectively. Combined with UV-vis DRS results, the calculated conduction bands are -0.79 and -0.53   eV, respectively. The study found that efficient separation between photogenerated holes and electrons in the heterostructure had a crucial impact on its photocatalytic performance.