Study of the Impact of S/N Codoping on the Antibacterial and Catalytic Properties of Fe ₂ O ₃ /ZnO Nanocomposites

Zinc oxide nanoparticles (ZnO‐NPs) are widely favored due to their low toxicity, biodegradability, and stability. However, their large energy bandgap, tendency for electron–hole recombination, and high exciton binding energy limit their effectiveness in catalytic, antimicrobial, and other applications. To address these limitations, ZnO‐NPs can be combined with metal oxides, such as iron oxide (Fe 2 O 3 ), and further doped with elements such as nitrogen (N) and sulfur (S) to enhance their antibacterial, electrochemical, and photocatalytic capabilities. In this research, pure ZnO‐NPs, Fe 2 O 3 ‐ZnO nanocomposites, and S/N‐codoped Fe 2 O 3 ‐ZnO nanocomposites were prepared using a precipitation technique. These samples were extensively characterized through various methods to verify their composition, crystallinity, crystallite size, functional groups, and morphology. The photocatalytic performance was evaluated by subjecting methylene blue (MB) dye to visible light in the presence and absence of the synthesized materials. Findings revealed that incorporating Fe 2 O 3 into ZnO and doping with N and S lowered the bandgap energy of pure ZnO‐NPs from 2.96 eV to 2.50 eV, substantially enhancing their photocatalytic and antibacterial activities. After 120 min of visible light exposure with continuous stirring, the optimized S/N‐codoped Fe 2 O 3 ‐ZnO nanocomposites achieved a MB degradation efficiency of 98.5%, notably surpassing the 78% efficiency of pure ZnO‐NPs. Additionally, the inclusion of Fe 2 O 3 and doping with S and N significantly improved the electrochemical and antimicrobial performance. The N/S‐codoped Fe 2 O 3 ‐ZnO nanocomposites demonstrated superior photocatalytic, antibacterial, and electrochemical properties compared to both pure ZnO‐NPs and Fe 2 O 3 ‐ZnO nanocomposites. These enhancements are primarily attributed to the reduced bandgap, increased surface area, and diminished electron–hole recombination resulting from Fe 2 O 3 incorporation and N/S codoping.