Effects of ZnO-Doping on the Morphology and Mechanical Properties in TiO2/SiO2 Nanocomposite Thin Films Via Sol–Gel Process for Coating Application

This paper presents the synthesis of a ZnO-doped SiO2–TiO2 nanocomposite using the sol-gel method. The spin-coating technique was employed to deposit the nanocomposite thin film onto a glass substrate. The ZnO doping ratio varied from 0 to 5%, and the thin films were calcined at temperatures ranging from 100 to 300°C for 2 h in air. FE-SEM images indicate that the films exhibit homogeneous, crack-free surface morphologies. The hardness of the ZnO-doped TiO2–SiO2 nanocomposite thin films is influenced by several factors, including ZnO doping concentration, heating temperature, and the molar ratio of [Ti]/[Si]. The ZnO-doped TiO2–SiO2 nanocomposite thin films show high transmittance in the visible region, are uniformly dispersed on the membrane surface, and have an average size of approximately 20–50 nm. These nanocomposite thin films can serve as protective coatings, enhancing UV resistance and scratch resistance while maintaining desirable required aesthetics.