中文摘要：

利用Ti与H2O2直接氧化法、TiF4水解法及溶胶-凝胶法分别制备了不同纳米结构的TiO2光催化薄膜，研究了这些薄膜光催化降解Rhodamine B（RB）染料的效率．结果发现，不同纳米结构薄膜光催化降解RB的效率与薄膜在室温条件下陈放时间存在着一定的关系，即随着陈放时间的延长，薄膜的光催化性能有不同程度的提高，最后达到一个相对稳定的值，这种现象被称为“自然时效”，它的存在与否和薄膜的表面形貌、晶体结构及制备技术等无关．通过平行实验结果分析，认为“自然时效”现象的产生主要是由于薄膜表面羟基的形成引起的．

英文摘要：

Titania thin films with different nanostructures were fabricated through various techniques of direct oxidation of Ti sheet with hydrogen peroxide, hydrolysis of TiF4, and sol-gel dip-coating. Abilities of the prepared titania films to assist photodegradation of Rhodamine B in water were studied. The photodegradation rate correlates closely to the preservation time of the titania films under ambient conditions. With prolonged preservation time, the photocatalytic property of the films gradually increases and finally reaches a stable value, which is called as ＂natural ageing＂. The phenomenon of ＂natural ageing＂ is irrelevant to the surface morphology, crystal structure and fabrication route of the titania thin films. Parallel experiments designed for this phenomenon indicate that the ＂natural ageing＂ behavior attributed mainly to the production of beneficial hydroxyl groups on the titania surface.