纳米TiO_2粉末的结构表征:X射线衍射、透射电镜及高温Raman光谱分析

Structural characterization of nanocrystalline TiO2 powders by X-ray dif fractometer, transmission electron microscopy and high temperature Raman spectroscopy

采用沉淀-胶溶-絮凝法,以偏钛酸为反应物,制备出锐钛矿型纳米TiO2 粉末,用X射线衍射(XRD)、透射电镜(TEM)和高温Raman光谱对其结构进行表征。并采用高温Raman光谱仪对所制备的纳米TiO2从25～1200℃进行了原位Raman光谱研究。温度较低时,锐钛矿相的Raman谱峰明显可见,由于高温下Raman信号减弱,随着温度升高,Raman特征谱峰逐渐减弱以至于全部消失,仅显示出几个宽宽的凸起。同时,高温Raman光谱存在明显的温度效应,因而导致了随温度升高144cm-1和196cm-1谱峰的蓝移,640cm-1谱峰的红移以及谱峰宽化。

Nanocrystalline anatase TiO2 powders were prepared by the method of precipitation-solution-gelation, using H2TiO3 as re-actants. The structure of nanocrystalline TiO2 was characterized by X-ray diffractrometer, transmission electron microscopy and high temperature Raman spectroscopy. Raman spectra of nanocrystalline TiO2 were in-situ measured from 25℃ to 1200℃ with a high temperature Raman spectroscopy. Raman features for anatase phase were clearly visible at lower temperatures. However, with the increase of the temperature, Raman features gradually reduced and only broad bands were exhibited, due to the weakening of Raman signals at high temperature. And the obvious temperature effect existed in high temperature Raman spectra, which led to 144cm-1 and 196cm-1 peaks blue-shifting, 640cm-1 peak red-shifting and Raman line broadening with temperature increasing.