Engineering Intralayer Anisotropy in Covalent Organic Frameworks
Yao Chai1, Yanmei Chen2, Shu-He Han1
1Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, 999077, China.
Angewandte Chemie (International Ed. in English)
|December 20, 2025
Summary
Researchers engineered covalent organic frameworks (COFs) with tunable anisotropy using a mixed-linker strategy. Shortening linkers enhanced charge carrier mobility and photocatalytic efficiency for NADH oxidation and near-infrared applications.
Area of Science:
- Materials Science
- Nanotechnology
- Photocatalysis
Background:
- Controlling intralayer anisotropy in 2D covalent organic frameworks (COFs) is crucial for advanced materials design.
- Existing methods often lack precise control over anisotropy, limiting performance in applications like photocatalysis.
Purpose of the Study:
- To develop a novel mixed-linker strategy for precise in-plane anisotropy tuning in COFs.
- To investigate the impact of linker length on electronic properties and photocatalytic activity.
Main Methods:
- Synthesized 1D nanoribbons using 8-connected pyrene/triphenylamine and 4-connected ETTA monomers.
- Longitudinally stitched nanoribbons with diamines of varying lengths to tune anisotropy.
- Characterized material properties and evaluated photocatalytic performance in NADH oxidation and near-infrared light applications.
Main Results:
- Shortening linkers (T-COF-1 vs. T-COF-2) induced strain, enhancing π-electron delocalization and quadrupling charge carrier mobility.
- T-COF-1 achieved 93.81% conversion efficiency in visible-light NADH oxidation, a 4.26-fold improvement.
- Demonstrated significant activity under near-infrared light (14.67% conversion), indicating potential for photodynamic therapy.
Conclusions:
- Established interchain covalent proximity as a key design principle for high-performance COF photocatalysts.
- The developed strategy enables rational engineering of COFs for enhanced solar energy conversion and biomedical applications.
- Tunable anisotropy in COFs opens new avenues for efficient photocatalysis and photodynamic therapy.
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