CAJ | 학술논문

Rare earth (Y, La and Nd) doped TiO2 thin films were prepared on glass slides by sol-gel method. The photocatalytic de-composition of methylene blue in aqueous solution was used as a probe reaction to evaluate their photocatalytic activities. The effects of hydroxyl groups on hydrophilic and photocatalytic activities were investigated by means of techniques such as X-ray diffrac-tion (XRD), atomic force microscopy (AFM), Fourier transform infrared (FTIR), optical contact angle, UV-Visible spectroscopy and VIS spectroscopy. The results showed that an appropriate doping of rare earth could cause the TiO2 lattice distortion, inhib-ited phase transition from anatase to rutile, accelerated surface hydroxylation and produced more hydroxyl groups, which resulted in a denser surface and smaller grains (40–60 nm), and a significant improvement in the hydrophilicity and photoreactivity of TiO2 thin films. The optimal content of rare earth was between 0.1 wt.%and 0.3 wt.%. Moreover, the modification mechanism of rare earth doping was also discussed.