Ti掺杂核壳结构晶态@非晶WO_(3)纳米线复合薄膜的制备与电致变色性能

Synthesis and electrochromic properties of Ti-doped core-shell crystalline@amorphous WO_(3) nanowire composite films

WO_(3)的结晶程度对其电致变色特性有很大影响,本研究首先使用溶剂热法制备晶态WO_(3)垂直纳米线阵列,随后采用磁控溅射技术在其表面包裹一层Ti掺杂氧化钨(WO_(3)-Ti)非晶态薄膜,从而得到晶态WO_(3)@非晶态WO_(3)-Ti核壳复合阵列结构。通过SEM与TEM可以观察到非晶态薄膜的厚度约为3~7 nm,并且非晶层的沉积并不破坏纳米线阵列结构。相比于纯WO_(3)纳米线,核壳纳米线的吸收峰发生了轻微红移,且XPS检测到复合前后W4f与Ti2p特征峰产生了明显的峰位移动,显示出核壳之间存在着界面交互作用。优化后WO_(3)@WO_(3)-Ti核壳纳米线的响应速度和着色效率分别是纯WO_(3)纳米线的2倍与1.8倍,在可见光和近红外区域都显示出良好的光学对比度,并且具有优异的循环稳定性,经过3000圈循环后对比度保持率可达95.8%。

The degree of crystallinity of WO_(3) has a great influence on its electrochromic properties.In this study,crystalline WO_(3) vertical nanowire arrays were first prepared by solvothermal method,and then a layer of Ti doped tungsten oxide(WO_(3)-Ti)amorphous film was wrapped on the surface by magnetron sputtering technology to obtain crystalline WO_(3)@amorphous WO_(3)-Ti core-shell composite array structure.It can be observed by SEM and TEM that the thickness of the amorphous film is about 3-7 nm,and the deposition of the amorphous layer does not destroy the nanowire array structure.Compared with pure WO_(3) nanowires,the absorption peaks of core-shell nanowires have a slight red shift,and XPS detected that the characteristic peaks of W4f and Ti2p before and after recombination have shifted significantly,confirming an interfacial interaction between the shell and the core.The switching speed and coloring efficiency of the optimized WO_(3)@WO_(3)-Ti core-shell nanowires are 2 times and 1.8 times that of the pure WO_(3) nanowires and the heterostructures exhibit good optical contrast in both visible and nearinfrared regions,and have excellent cycling stability,with a contrast retention rate of 95.8%after 3000 cycles.