Enhanced photocatalytic degradation performance of a novel ZnS/CdIn₂S₄ Z-type heterojunction

The development of innovative photocatalysts with high adsorption capacity and efficient charge separation capabilities represents a critical breakthrough in dye wastewater treatment. In this study, an eco-friendly Z-scheme heterojunction ZnS/CdIn₂S₄ composite photocatalyst was successfully synthesized through an innovative combination of hydrothermal synthesis and ultrasonic dispersion techniques. Experimental results demonstrated that the optimal ZnS/CdIn₂S₄ composite with a molar ratio of 2:1 achieved 93% degradation efficiency for methylene blue under visible light irradiation within 3 hours. Multidimensional characterization techniques were employed to elucidate the performance enhancement mechanisms: XPS analysis confirmed strong electronic coupling at the heterointerface, while SEM images revealed ZnS nanoparticles uniformly loaded on layered CdIn₂S₄. This synergistic effect originates from the internal electric field formed at the heterojunction interface, which not only shortens the migration distance of photogenerated electrons (<5 nm) but also promotes spatial charge separation through band bending. This research provides new insights for designing efficient and stable Z-scheme photocatalytic systems, demonstrating significant application potential in the treatment of dye-containing wastewater.