Fabrication of porous TiO2–SiO2 multifunctional anti-reflection coatings by sol–gel spin coating method

Abstract

In this study, we report that an antireflective coating with multifunctional properties, including high transparency, self-cleaning and abrasion resistance, was prepared by a facile sol–gel spin-coating method. The average transmittance of single coated glass substrates was greater than 93% in the wavelength range of 300–1000 nm compared to 90.1% for bare glass substrate. The photocatalytic activity of the coatings showed a close dependence on the content of TiO₂ nanoparticles. The coatings showed the ability to decompose air borne organic contaminants (gaseous benzene) and applied contaminants (fingerprints) under UV irradiation when the content of TiO₂ was greater than 10%. After illumination by UV light, the TiO₂–SiO₂ coatings showed hydrophilic properties with a water contact angle of about 1°, which favored greatly the self-cleaning function of the coatings. When the content of TiO₂ was 10%, the critical load of the coating increased up to 305 μN as compared to that of the base-catalyzed SiO₂ coating (198 μN), which indicated the abrasion resistance property of this coating. This approach suggested novel opportunities to a variety of practical applications, including windows of high rise buildings, solar thermal collectors and solar cell cover glasses, etc.