Preparation of highly transparent TiO₂/SiO₂ nanocomposite thin films with superhydrophilic self-cleaning properties

TiO₂/SiO₂ films with different molar ratios Ti/Si were prepared by a sol-gel method. The films not only have super hydrophilicity, but also have high light transmittance and self-cleaning properties. The superhydrophilicity of the film endows it with excellent anti-fog and anti-fouling properties, while its self-cleaning properties enable it to exhibit photocatalytic decomposition and removal of organic matters. Infrared spectroscopy and X-ray photoelectron spectroscopy indicate that silicon element has been successfully introduced into the bulk of TiO₂ crystal, which not only reduces the contact angle of water droplets on the film, but also improves the transparency of the film, making it suitable for use in optical devices such as lenses and mirrors. This superhydrophilic film can remove oleic acid on the film surface within a certain period of light exposure and maintain good hydrophilicity in a dark for 14 days, and it still exhibits stable superhydrophilic properties. The experimental results show that TiO₂/SiO₂ films with 10% silicon content have the best optical and photocatalytic properties when applied to glass substrates, while the energy spectrum of the XPS etching test shows that Si has been successfully introduced into TiO₂, which not only leads to a decrease in the contact angle of the water droplets on the film but also improves the light transmittance of the film, enabling it to be applied to the surface of silicon wafer-based materials such as lenses and solar cell panels.