Electrochromic (EC) materials have been regarded as important energy-saving materials in recent decades. However, some shortcomings, such as short cycle life, low light modulation, and slow response, have restricted the large-scale application of existing EC materials. To rectify this situation, elemental doping is a promising approach. In this work, titanium (Ti)-doped nanostructured nickel oxide (NiO) porous films have been prepared, and their EC performance and mechanism have been explored based on electrochemical tests and energy-band structure analysis. The results show that an appropriate level of Ti doping not only leads to improved EC performance, but also plays a certain role in regulating the microstructure, resistivity, semiconductor type, energy-level structure, and interfacial heterojunction structure of NiO films. Moreover, evaluation of the energy levels and band gaps of NiO films has indicated that Ti doping reduces the interfacial potential barrier of FTO/NiO. An NiO film doped with 2.0 wt% Ti showed optimum EC properties, including a short response time (bleaching time 0.8 s; coloring time 2.9 s), large light modulation (54.4%), high coloration efficiency (45.6 cm² C⁻¹), and long EC cycling life (50000 cycles). The Ti doping converted NiO from a p-type to an n-type semiconductor.

近几十年来，电致变色（EC）材料被认为是重要的节能材料。然而，现有EC材料存在循环寿命短、光调制率低、响应慢等缺点，制约了其大规模应用。为了纠正这种情况，元素掺杂是一种很有前途的方法。在这项工作中，制备了钛 (Ti) 掺杂的纳米结构氧化镍 (NiO) 多孔薄膜，并基于电化学测试和能带结构分析探索了它们的 EC 性能和机理。结果表明，适当的Ti掺杂水平不仅可以提高EC性能，而且对NiO薄膜的微观结构、电阻率、半导体类型、能级结构和界面异质结结构具有一定的调节作用。而且，对 NiO 薄膜能级和带隙的评估表明，Ti 掺杂降低了 FTO/NiO 的界面势垒。掺杂 2.0 wt% Ti 的 NiO 薄膜显示出最佳的 EC 特性，包括响应时间短（漂白时间 0.8 s；着色时间 2.9 s）、大光调制（54.4%）、高着色效率（45.6 cm²  C ^-1 )，EC 循环寿命长（50000 次循环）。Ti 掺杂将 NiO 从 p 型半导体转变为 n 型半导体。