Effect of sulfur-modified zinc oxide thin layers on structural, morphological, optical, and photocatalytic properties for environmental applications
No Thumbnail Available
Date
2025
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This 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 applications