Efficient photocatalytic degradation of TNT wastewater over CdS/ZnO heterojunction: Performance and mechanism

2,4,6-Trinitrotoluene (TNT), as a widely used energetic material, is prone to causing water pollution during its production, transportation and disposal processes. This poses a severe menace to the environment and human health. Therefore, the efficient treatment of TNT-polluted wastewater has grown into a popular research direction in the environmental field. Photocatalytic technology has great application prospects due to its environmental friendliness and thorough degradation. As a commonly used photocatalyst, nano-ZnO suffers from the drawbacks of a wide band gap that only responds to ultraviolet light and limited photocatalytic performance, and constructing heterojunctions is an effective strategy to enhance its performance. In this study, CdS/ZnO heterojunction composites were synthesized via the coprecipitation method. After optimizing the component ratio, the 4-CdS/ZnO exhibited a photocatalytic degradation efficiency of over 92% for TNT, with a degradation efficiency 20 times higher than that of pure ZnO. Moreover, cyclic experiments verified its excellent stability. The present study puts forward novel ideas and technical support for the green and efficient degradation of TNT-contaminated water bodies.