Sulfur vacancies-engineered CaIn2S4 microspheres for enhanced photocatalytic organic pollutant and antibiotic removal

It is an interesting research topic on construction of defect- rich structures to enhance the performance of photocatalysts. In this study, CaIn 2 S 4 photocatalyst containing sulfur vacancy was successfully synthesized using a straightforward solvothermal method. The sulfur vacancy concentration in CaIn 2 S 4 was controlled by adjusting the amount of thioacetamide added during preparation. Among the prepared samples, CaIn 2 S 4 -10 sample with excellent photocatalytic performance exhibits superior degradation efficiency (98.2 %) within 50 minutes when the initial methyl orange (MO) concentration was 20 mg/L. Similarly, it shows the highest degradation performance (94 %) against the antibiotic tetracycline hydrochloride (TCH) (20 mg/L). The phase structure, surface element composition, optical properties and other characteristics of the prepared samples were systematically investigated. The findings demonstrate that the CaIn 2 S 4 -10 sample exhibits a decreased band gap width and a negatively shifted conduction band position, which enhances its reduction ability and improves its photocatalytic activity.