Sol–gel synthesis of TiO2 nanostructured film on SiO2 pre-coated glass with a comparative study of solvent effect on the film properties

Abstract

TiO2 films on SiO2 pre-coated glass substrate were prepared by sol–gel dip-coating method. The effects of solvent type in the sol on crystalline structure, microstructure, optical properties, photocatalytic activity and hydrophilicity of the films were investigated. X-ray diffraction, scanning electron microscopy, atomic force microscopy, UV–Vis spectrophotometer and contact angle measurement were used for investigation of film properties. Isopropanol (i-PrOH), ethanol (EtOH) and methanol (MtOH) were used as the solvents. It was shown that the type of solvent affects TiO2 thin film properties. The layers of TiO2 on SiO2 pre-coated substrate after heat treatment were transparent in color and uniform in thickness and color. All TiO2 films prepared in this work were of the anatase phase and were orientated along the (101) plane. It was found that methanol had best effects on the photocatalytic and super-hydrophilic properties of TiO2 films. It might be due to smaller particle size of the crystallites in the sample derived from sol containing methanol.