摘要
报道了以钨粉为原料,采用溶胶 凝胶技术和旋转镀膜方法,制备出了气致变色WO3纳米薄膜。采用椭偏仪、X射线衍射仪(XRD)、场发射扫描电子显微镜(FE SEM)、红外光谱仪以及可见光分光光度计等方法分析了薄膜的特性。研究结果表明热处理使得薄膜致密,折射率增大,厚度减小,薄膜结晶;过氧键消失,WO3微结构发生了变化,共角W—O—W键吸收越来越强,且向高波数方向移动。这些变化归因于热处理导致的WO3颗粒形状、团聚状态的变化以及应变键的产生。WO3纳米薄膜具有很好的气致变色特性,致色与退色态透射率变化超过60%,变色起因于H扩散到WO3薄膜中形成的小极化子吸收。
Nano structured tungsten oxide films have been prepared using a sol-gel process with the starting tungsten powders together with the spin coating method in this paper. Properties of the WO_3 films have been investigated with ellipsometer, XRD, FE-SEM, FTIR and spectrophotometer, respectively. Thickness of the films decreases with the annealing temperature increasing, while refractive index of the films increases from 1.83 to 2.01; the films become more and more dense and crystallize after annealed at a temperature above 350℃. IR spectroscopy revealed that the absorption of the corner-sharing mode in the films increases, and the peak shifts to a higher wave number during the annealing. These were attributed to a change of WO_3 particle shape and state of aggregation of the particles in the films as well as the formation of strained W-O-W bonds with disappearance of the network-terminated OH groups during the annealing. The nano structured WO_3 films have an excellent gasochromic property with a more than 60% change of the average visible transmittance between the colored and bleached states. The gasochromism was due to the absorption of polarons in the films caused by H insertion.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2003年第6期707-710,共4页
Journal of Functional Materials
基金
国家自然科学基金资助项目(69978017)
