Synthesis and characterization of ZnS and Ag-ZnS nanoparticles for photocatalytic degradation of aqueous pollutants

Photocatalytic degradation has drawn much interest recently as a substitute technique for eliminating environmental contaminants from the aqueous phase. In this study, pure and Ag-doped zinc sulfide (ZnS) nanoparticles were synthesized for the photocatalytic degradation of methylene blue (MB) under UVA light irradiation using a simple chemical co-precipitation method. The nanopowders' structural, optical, morphological, and chemical properties were characterized using XRD, FTIR, UV-Vis, and FESEM techniques. XRD analysis confirmed the hexagonal crystal structure of the nanoparticles, while FTIR identified stretching vibrations corresponding to O–H, C–H, C=O, C–N, and Zn–S bonds. The UV-Vis analysis revealed an optical band gap in the range of 5.2–5.4 eV. Photocatalytic performance tests under UVA light demonstrated that Ag doping significantly enhanced the photocatalytic efficiency of ZnS nanoparticles in degrading MB. Upon exposure to UVA light, the synthesized Ag-ZnS nanoparticles achieved impressive decolorization efficiency within 25 minutes, compared to 35 minutes for pure ZnS. The findings indicate that Ag-ZnS is a highly promising photocatalyst for the efficient removal of aqueous pollutants, including methylene blue dye.