Effect of hydroxyl groups on hydrophilic and photocatalytic activities of rare earth doped titanium dioxide thin films

• Published in: Journal of rare earths 2015-02, Vol.33 (2), p.148-153
• Main Author: 杜军 吴其 钟汕 顾馨 刘娇 郭海志 张文龙 彭海龙 邹建国
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; Doping; Fourier transforms; hydrophilicity; Hydroxyl groups; Photocatalysis; photocatalytic activity; rare earth; Rare earth metals; Spectroscopy; Thin films; TiO2; TiO2薄膜; Titanium dioxide; 二氧化钛薄膜; 亲水性; 光催化活性; 原子力显微镜; 可见光谱; 稀土掺杂; 羟基化
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(14)60395-1

Rare earth（Y, La and Nd） doped TiO2 thin films were prepared on glass slides by sol-gel method. The photocatalytic decomposition 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 diffraction（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, inhibited 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.