Preparation of TiO2–SiO2 film with high photocatalytic activity on PET substrate

Abstract TiO2–SiO2 films were successfully deposited on modified poly (ethylene terephthalate) (PET) substrate as one of the thermal-sensitive material with different content of SiO2. The as-prepared films were characterized with Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), respectively. At the ratio of Ti / Si = 1 : 1, the TiO2–SiO2 thin film showed the highest photocatalytic activity due to improving the ability of the surface adsorption and increasing surface hydroxyl group in the composite thin film. Moreover, the SiO2–TiO2 composite thin film showed the most surface roughness, which further confirms the film with the highest photocatalytic activity at the ratio of Si / Ti = 1 : 1. When the ratio of Si / Ti more than 1 : 1, the decrease in photocatalytic activity is due to reducing amount of the surface acidity sites and photocatalytic center.