Synthesis, Characterization, and Antibacterial Activity of Ag-TiO2-Fe Composite Thin Films

Ag-TiO2-Fe composite thin films with different Ag contents are deposited onto a glass substrate by a thermal evaporation method. TiO2, TiO2-Fe, and Ag-TiO2-Fe thin films are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV-vis-NIR spectroscopy, and photoluminescence (PL) to study the relation between their structural, morphological, optical, and luminescent properties with their antibacterial activities. XRD and Raman measurements show the formation of the anatase phase with increasing silver content in Ag-TiO2-Fe composite thin films. SEM images show the presence of silver in the metallic form. Optical measurements display a redshift in the optical absorption edge of TiO2-Fe and Ag-TiO2-Fe composite films with a decrease in the energy bandgap compared to pure TiO2. The antibacterial activity of the films against Escherichia coli is investigated both in the dark and under UV light. It is found that Ag plays a major role on the antibacterial efficiency in the dark. Ag-TiO2-Fe composite thin films exhibit a synergistic antibacterial effect under UV light, resulting an excellent antibacterial coating.

Automated summary

Ag-TiO2-Fe composite thin films with different Ag contents were deposited onto a glass substrate by thermal evaporation. The films were characterized to investigate the relationship between their structural, morphological, optical, and luminescent properties with their antibacterial activities. The results showed the formation of the anatase phase with increasing silver content in the films, and the presence of metallic silver. The films exhibited a redshift in the optical absorption edge and a decrease in the energy bandgap compared to pure TiO2. The antibacterial activity of the films was found to be influenced by the presence of silver, with a synergistic effect observed under UV light.