TiO2-PTPAT纳米核/壳结构复合膜的制备及电致变色性能

通过水热法在氟掺杂氧化锡(FTO)导电玻璃基底上制备了垂直生长的二氧化钛(TiO₂)纳米棒阵列, 以TiO₂纳米棒阵列为模板采用电化学聚合法, 原位制备了TiO₂-聚三2-(4-噻吩)苯]胺(PTPAT)纳米核/壳结构的复合薄膜, 相比于纯PTPAT薄膜, TiO₂-PTPAT复合薄膜显示出更好的电致变色(EC)性能. PTPAT薄膜在600 nm波长下的对比度为28%, 在1100 nm波长下的对比度为60%, 其褪色时间为3.86 s, 着色时间为5.52 s; TiO₂- PTPAT复合薄膜在600 nm波长下的对比度为43%, 在1100 nm波长下的对比度为79%, 其褪色时间为3.35 s, 着色时间为4.43 s, 表明核/壳复合结构薄膜的光学对比度和响应时间性能更加优异. 将PTPAT薄膜和TiO₂-PTPAT复合薄膜作为电致变色层组装成固态EC器件, 基于复合薄膜的器件具有更好的循环稳定性和更高的耐受电压. 复合薄膜在保持PTPAT薄膜原有的EC性能的基础上, 由于有序生长的纳米阵列结构的引入增加了薄膜的比表面积, 为电致变色过程中离子的掺杂和脱掺杂提供了更多有序通道, 从而加快了离子扩散速度. TiO₂阵列的引入也改善了聚合物薄膜与透明导电电极之间的界面结合情况, 从而提升了器件的稳定性.

Preparation and Electrochromic Properties of TiO2-PTPAT Nano Core/Shell Composite Films

The vertically grown TiO₂ nanorod array was prepared on fluorine-doped tin oxide（FTO） con- ductive glass substrates via hydrothermal method， and then TiO₂-poly（tris［4-（thiophen-2-yl）phenyl］amine） （PTPAT） core/shell structure composite films were prepared by in?situ electrochemical polymerization using TiO₂ nanorod arrays as templates. Compared with the pure PTPAT film， the composite film showed well electrochromic（EC） properties. The optical contrast of PTPAT film is 28% at 600 nm， 60% at 1100 nm， and the discoloring time is 3.86 s and the coloring time is 5.52 s at 1100 nm； the optical contrast of TiO₂-PTPAT compo- site film is 43% at 600 nm， 79% at 1100 nm， and the discoloring time is 3.35 s and the coloring time is 4.43 s at 1100 nm. The results show that the core/shell composite structure film has better optical contrast and swit- ching time performance. The PTPAT film and the TiO₂-PTPAT composite film are used as the EC layer to assemble EC solid devices. The composite film-based devices show better cycle stability and higher withstand voltage. This is because the composite film maintains the original electrochromic properties of the PTPAT film. Due to the introduction of orderly grown nano-array structure， the specific surface area of the film is increased， and more ordered channels are provided for the doping and dedoping of ions in the electrochromic process， thereby accelerating the ion diffusion speed. At the same time， the introduction of TiO₂ array improves the interface bonding between the polymer film and the transparent conductive electrode， thus improves the stability of the device.