Two-Dimensional Semiconducting Covalent Organic Frameworks with Unidirectional Fused-Ring Bands
Yaoqian Feng1, Xiaoyi Xu1, Kai Xu1
1State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Journal of the American Chemical Society
|October 29, 2025
Summary
Researchers developed novel conductive covalent organic frameworks (COFs) with fused-ring structures for enhanced electronic properties. These materials show promise for next-generation organic semiconductors and electrocatalysts.
Area of Science:
- Materials Science
- Organic Chemistry
- Nanotechnology
Background:
- High-performance conductive covalent organic frameworks (COFs) require integrated long-range conjugated fused-ring structures, which are challenging to synthesize.
- Existing COF architectures often lack the necessary electronic properties for advanced applications.
Purpose of the Study:
- To design and synthesize novel two-dimensional (2D) COFs featuring unidimensional fused-ring structures.
- To investigate the electronic and catalytic properties of these new COF materials.
Main Methods:
- Metal ion-mediated metal tetraaza[14]annulene (MTAA) ring formation from nonfused-ring precursors.
- Characterization of the resulting 2D COFs' structural, optical, and electrical properties.
Main Results:
- Four new 2D COFs with interconnected, parallel linear conjugated fused-ring bands were successfully synthesized.
- The COFs exhibit a narrow optical bandgap (<1 eV), high conductivity (10^-3 S cm^-1), and significant carrier mobility (10^-1 cm^2 V^-1 s^-1).
- CoTAA-COF-1 demonstrated a high oxygen reduction reaction (ORR) half-wave potential (0.84 V) in alkaline media.
Conclusions:
- A viable strategy for constructing fused-ring COFs was established, enabling the development of narrow-band-gap organic semiconductors.
- The synthesized COFs show potential as high-performance electrocatalysts, particularly for the ORR.
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