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TiO2-SiO2 composite materials with different composition (from 0 to 50 mol % SiO2) were prepared by sol-gel method. Microstructure, optical property and photocatalytic activity of TiO2-SiO2 composite materials were characterized by Raman scattering, ultraviolet-visible (UV-vis) spectrometer and photocatalytic degradation of methylene blue. The Raman spectra results showed that TiO2-SiO2 composite materials contained only a single crystalline phase of anatase TiO2. It also indicated the inclusion of SiO2 suppressed the growth of anatase TiO2. The UV-vis absorption spectra showed that the absorption edge of TiO2-SiO2 composite materials has a blue shift as the SiO2 increased. The optical band gap of TiO2-SiO2 increased from 3.06 eV to 3.32 eV for TiO2 and 0.5TiO2-0.5SiO2. The adsorption performance and photocatalytic activity of TiO2-SiO2 was enhanced with the increase of SiO2 content. 0.5TiO2-0.5SiO2 has the best absorption performance and photocatalytic activity in our experiment. And it has potential application value in the field of photocatalytic materials.

xTiO2- (1-x) SiO2 composite thin films with x=1.0, 0.9, 0.7, 0.5 were dip-coated on glass substrates by sol-gel method. The effects of composition on the microstructure, wettability and optical properties were investigated by X-ray diffraction (XRD), contact angle tester and ultraviolet visible spectrophotometer. Results showed that only the anatase diffraction peaks of TiO2 were found in composite materials. With the increase of SiO2 concentration, the crystallization degree of the composite material decreased slightly. The hydrophilicity was enhanced after coating on glass substrates. The water contact angle of TiO2 film was the smallest in all the films. All the composite films were transparent in visible wavelength. And the average transmittance of 0.5TiO2-0.5SiO2 was highest. The sharp decrease of transmittance was observed in the transmittance spectra, which was related to absorption of photos by electron in valence band.

TiO2, SiO2 and TiO2-SiO2 thin films were prepared by sol-gel dipping method on glass substrates. The pyrolysis behavior of TiO2 and SiO2 dry gel were tested by differential thermal analysis (DTA). The microstructure and optical properties of the TiO2, SiO2 and TiO2- SiO2 were studied by X-ray diffraction (XRD) and ultraviolet and visible spectrophotometer. The results showed that the phase structure of the films was affected by the composition. All the films were transparent in the visible region. Meanwhile, the transparency of SiO2 was better than TiO2 and TiO2-SiO2 composite film. The ban-gap of the TiO2, SiO2 and TiO2-SiO2 thin films were 3.79, 4.01 and 3.91.