Engineering ZnIn₂S₄ Nanosheets with Zinc Vacancies: Unleashing Enhanced Photocatalytic Degradation of Tetracycline

Defect engineering is a highly effective strategy for accelerating charge transfer and enhancing the performance of photocatalysts. In this study, ZnIn₂S₄ nanosheets were designed and prepared with controlled Zn vacancies to optimize the electronic band structure and localized charge density of ZnIn₂S₄. EPR results confirmed the formation of Zn vacancies. This modification enabled efficient capture of photoexcited charges in defect centers, thereby prolonging the carrier's lifetime. Theoretical calculations demonstrated that these vacancies induced the formation of new defect states and highly efficient surface reaction sites. As anticipated, under visible light irradiation, the photocatalytic tetracycline removal rate of the ZnIn₂S₄ nanosheets with Zn vacancies reached 82.8% within 60 min, significantly higher than that observed for the pristine ZnIn₂S₄ sample. These findings offer valuable insights into the deliberate construction of metal-vacancy-containing photocatalytic nanomaterials for the enhanced degradation of micropollutants.