Hydrophobic ZnIn2S4 Bulk‐phase Homojunctions for Efficient Photodegradation of Lignin

Lignin and its derivatives in paper wastewater contain phenolic structures, high molecular weights, and complex structures, resulting in low photocatalytic degradation efficiency and difficult mineralization. In this study, a cationic surfactants in‐situ modification strategy was used to prepare hydrophobic ZnIn2S4 bulk‐phase homojunctions for efficient lignin degradation. TG, static contact angle, and EPR tests showed that the modification of CTA+ on ZnIn2S4 increased with the increase in the addition of TAA, boosting the photocatalyst’s hydrophobicity and introducing more metal defects. PL and electrochemical analyses indicate that appropriate metal defects can form ZnIn2S4 bulk‐phase homojunctions, thereby reducing the carrier complexation rate. Meanwhile, the enhancing hydrophobicity of catalyst promotes the adsorption of lignin and O2, which improves the surface reaction efficiency of the photocatalytic process. After 40 minutes of simulated sunlight illumination, the degradation rate of lignin by ZIS‐10 reached 95%, which was 12.9 times higher than that of ZIS, with the mineralization rate of 74%. This study offers new insights into the construction of bulk‐phase homojunctions for the efficient degradation of phenolic and other difficult‐to‐degrade organic pollutants.