Oriented Two-Dimensional Covalent Organic Framework Films for Near-Infrared Electrochromic Application.
Qing Hao1, Zhi-Juan Li1, Cheng Lu1
1University of the Chinese Academy of Sciences , Beijing 100049 , P. R. China.
Journal of the American Chemical Society
|November 21, 2019
Summary
This study reports on a triphenylamine-based two-dimensional covalent organic framework (2D COF) film exhibiting reversible color changes for electrochromic devices. The material shows potential for applications in the visible and near-infrared regions.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Triphenylamine-based materials are explored for their electronic properties.
- Two-dimensional covalent organic frameworks (2D COFs) offer tunable structures for advanced applications.
- Electrochromic materials change color upon electrical stimulation, enabling smart window and display technologies.
Purpose of the Study:
- To investigate the electrochromic properties of a novel triphenylamine-based 2D COF film.
- To construct and evaluate a quasi-solid-state electrochromic device using the 2D COF film.
- To characterize the film's structure, crystallinity, and orientation on an indium tin oxide (ITO) substrate.
Main Methods:
- Fabrication of a 2D COF film (COF3PA-TT) on ITO-coated glass.
- Film characterization using techniques to assess uniformity, crystallinity, and orientation.
- Electrochemical and spectroelectrochemical measurements to study electrochromic behavior.
- Assembly of a quasi-solid-state electrochromic device.
Main Results:
- The COF3PA-TT film demonstrated uniform and crystalline structure, oriented parallel to the substrate.
- Reversible color transitions between deep red and dark brown were observed during redox processes.
- Spectroelectrochemical analysis revealed color changes in visible and near-infrared regions, indicative of intervalence charge transfer.
- The fabricated device showed moderate performance and stability, particularly in the near-infrared spectrum.
Conclusions:
- The triphenylamine-based 2D COF film exhibits promising electrochromic properties.
- The material is suitable for integration into electrochromic devices, with potential for near-infrared applications.
- Further research can optimize device performance and explore broader applications of these oriented 2D COF films.
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