Synthesis and characterization of co-doped TiO2 thin films on glass-ceramic

Abstract

In this research, an attempt was made to improve TiO2 photo-catalyst properties, thus pure, N–Ce co-doped TiO2 thin films were prepared on glass-ceramic substrate using a sol–gel dip-coating technique. The samples were calcinated in air at 475°C, 550°C, and 650°C for 2h. The result of simultaneous thermal analysis (STA) and X-ray diffraction (XRD) showed that the presence of Ce in TiO2 could inhibit the phase transformation from anatase to rutile and enhance the thermal stability, and anatase was the dominant phase in N–Ce co-doped TiO2 samples. Also based on the results, the doping results in decreasing the size of TiO2 crystallite. The results of ultra violet-visible light diffuse reflectance spectra (UV–vis DRS) presented that cerium doping results in a shift in the absorption spectra of N–Ce co-doped TiO2 to the visible region. The photo-induced hydrophilicity and photo-catalytic activity of the films were evaluated by the water contact angle measurement and photo-catalytic degradation of aqueous methyl orange, respectively. It was found that N–Ce co-doped TiO2 thin films showed a higher photo-catalytic activity, and better photo-induced hydrophilicity than the pure TiO2 thin films. However, too much doping did not improve properties of N–Ce co-doped TiO2. The results of the experiments showed that doping with Ce content of Ce/Ti% equal to 3% and N content of urea/tetra n-butyl ortho titanate equal to 0.25 can improve N, Ce co-doped TiO2 properties.