Khemissi, Lahouel2026-10-012026-10-012025http://dspace.univ-khenchela.dz:4000/handle/123456789/11606This study investigates the impact of sulfur (S) doping on the structural, surface morphological, and optical properties of zinc oxide (ZnO) thin films, alongside their potential applications in photocatalysis. X-ray diffraction (XRD) analysis confirmed that the films maintained a hexagonal structure without any impurities or additional phases. The incorporation of 2 wt% S into ZnO led to a reduction in crystallite size from 26.71 nm to 24.59 nm. Scanning electron microscopy (SEM) images showed modifications in surface morphology due to the doping process. Energy dispersive X-ray Spectroscopy (EDS) analysis confirmed the presence of S in the films. Atomic force microscopy (AFM) analysis revealed an increase in root mean square (RMS) roughness from 3.321 nm to 3.879 nm following doping. Ultraviolet-visible (UV-VIS) spectroscopy measurements indicated a decrease in the band gap for the 2 % S-doped ZnO sample from 3.26 eV for pristine ZnO to 3.23 eV. The 2 %-doped ZnO sample exhibited enhanced efficacy in degrading methylene blue dye when exposed to UV and sunlight. The trapping test identified • OH and h + as the primary active species in the photocatalytic processes. Additionally, the thin film demonstrated improved stability and reusability after six recycling cycles, suggesting its potential for wastewater treatment. Thus, S-doped ZnO emerges as a promising material for environmental applicationsenArticle