Synthesis, Characterization, and Antibacterial Activity of Ag–TiO<sub>2</sub>–Fe Composite Thin Films
Djihad Grine, Hocine Akkari, Paloma Fernández, Tahar Mekhalif, Salim Hassani, Fouaz Lekoui
Abstract
Ag–TiO 2 –Fe composite thin films with different Ag contents are deposited onto a glass substrate by a thermal evaporation method. TiO 2 , TiO 2 –Fe, and Ag–TiO 2 –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–TiO 2 –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 TiO 2 –Fe and Ag–TiO 2 –Fe composite films with a decrease in the energy bandgap compared to pure TiO 2 . 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–TiO 2 –Fe composite thin films exhibit a synergistic antibacterial effect under UV light, resulting an excellent antibacterial coating.