A green chemistry approach to the facile and scalable synthesis of antibacterial Fe-doped ZnO nanoparticles for industrial and commercial applications

• Fe-doped ZnO nanoparticles were synthesized via a simple sol–gel method with tunable Fe concentrations. • Doping with Fe (1–4%) significantly enhances antibacterial activity against Staphylococcus aureus and Escherichia coli . • XPS analysis confirms Fe exists in mixed valence states (Fe 2+ /Fe 3+ ), promoting redox-driven ROS generation. • Bandgap narrowing via Fe doping improves visible light absorption, enhancing photocatalytic antibacterial effects. • Strong dose-dependent antimicrobial effects were observed through inhibition zone, CFU, and growth curve assays. • The study demonstrates the potential of Fe-doped ZnO NPs as effective antibacterial agents, especially for antibiotic-resistant pathogens. This study explores the green and low-cost synthesis of iron-doped zinc oxide nanoparticles (Fe-doped ZnO NPs) using a simple, scalable sol–gel method under mild conditions. The novelty of this work lies in the combination of industrial scalability, eco-friendly processing, and cost-effectiveness, which together enable sustainable production of high-performance nanomaterials. Fe doping was employed to enhance the photocatalytic and antibacterial properties of ZnO by promoting reactive oxygen species (ROS) generation and bandgap narrowing, thereby improving light absorption and antimicrobial efficiency. The synthesis utilized water and ethanol as solvents, ensuring an environmentally benign process that avoids hazardous reagents. The Fe-doped ZnO NPs were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), confirming the successful incorporation of Fe into the ZnO lattice with well-defined crystalline structures. The nanoparticles exhibited strong antibacterial activity against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, with enhanced inhibition observed at higher Fe concentrations. Furthermore, a preliminary cost analysis demonstrated the economic viability of the sol–gel route for large-scale industrial production. The study highlights the potential of Fe-doped ZnO NPs synthesized via a green, scalable, and cost-effective approach for applications in coatings, food packaging, and biomedical fields.