溶胶—凝胶工艺制备的TiO_2纳米薄膜及其表面结构

TiO_2 nanometer thin film prepared by sol gel processing and its surface structure

采用溶胶—凝胶工艺在玻璃表面制备了均匀透明的锐钛矿型ＴｉＯ２ 纳米薄膜， 其颗粒大小在４０ ～８０ ｎｍ 。薄膜的Ｘ 射线衍射分析表明， 当薄膜的厚度小于０ ．４５ μｍ 时， 薄膜中未出现明显的锐钛矿的衍射峰。Ｘ 射线光电子能谱（ＸＰＳ） 和电子自旋共振谱（ＥＳＲ） 的实验结果表明： 薄膜中除含有Ｔｉ， Ｏ 元素外， 还有一定量的来自有机前驱物中未完全燃烧的碳和少量从玻璃表面扩散到薄膜中的Ｎａ 和Ｃａ 元素； Ｔｉ 元素除了以＋ ４ 价形式存在外， 还有一定量的Ｔｉ 以＋ ３ 和＋ ２ 价形式存在。ＴｉＯ２ 薄膜在５３０ ｎｍ附近的宽吸收带也证实了ＴｉＯ２ 薄膜中低价钛元素的存在。

The uniform transparent anatase nanometer TiO 2 thin films were deposited on glass substrates by sol gel processing. The diameters of TiO 2 particles in the thin films are in the range of 40～80 nm. When the thickness of the films is lower than 0.45 μm, XRD patterns of films show no peak of anatase. The chemical composition and the valency state of the film were analyzed with X ray photoelectron spectroscopy(XPS) and electron spin resonance(ESR). Experiment results show that besides Ti and O elements, there is a certain amount of residual carbon from the starting organometallic components and a small amount of sodium and calcium ions diffused from the glass substrates. Although the valency state of Ti element mainly exist in oxides of Ti(Ⅳ), there is a certain amount of oxides of Ti(Ⅲ) and Ti(Ⅱ). The ultraviolet visible spectra of the TiO 2 thin films appear the wide adsorption band in the wavelength about 530 nm, which further confirms that there are a certain amount of oxides of Ti(Ⅲ) and Ti(Ⅱ) in the TiO 2 thin films.