铈掺杂二氧化钛的化学态分析

Analysis of Chemical States of Ce-doped TiO_2

采用溶胶-凝胶法制备纯TiO2粉末和5mol%Ce掺杂TiO2粉末,利用X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)和紫外-可见分光光度计(UV-Vis)表征样品的相变过程和化学态变化,主要探讨了Ce掺杂对TiO2相变温度、物相组成、化学态及吸收光谱范围的影响。结果表明:掺杂Ce抑制了TiO2的相转变和晶粒长大。随着热处理温度升高,Ce掺杂TiO2的晶格氧峰增强而吸附氧峰降低,而且Ti2p3/2结合能减小,Ce3+逐渐被氧化为Ce4+。掺杂Ce拓宽了TiO2的可见光谱吸收范围。

Titania powders and 5mol% Ce-doped TiO2 powders were synthesized by sol-gel method. The influence of Ce dopant on the phase transformation temperature,phase compositions,chemical states and the visible light absorbable range of titania were investigated by X-ray diffractometer（ XRD）,transmission electron microscopy（ TEM） and UV-Vis spectrophotometer（ UV-Vis）. The results show that Ce dopant inhibits the phase transformation and grain growth of titania. As the heat treatment temperature of Cedoped titania increases,lattice oxygen peak is enhanced,while absorption oxygen peak is reduced.Meanwhile,Ti2p3 /2binding energy is decreased,and Ce3 ＋was gradually oxidized to Ce4 ＋. In addition,the Ce-doped increases the visible light absorbable range of titania.