Quasi-Three-Dimensional Cyclotriphosphazene-Based Covalent Organic Framework Nanosheet for Efficient Oxygen Reduction
Jianhong Chang1, Cuiyan Li1, Xiaoxia Wang2
1State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
Nano-Micro Letters
|June 29, 2023
Summary
Metal-free covalent organic frameworks (COFs) were synthesized for oxygen reduction reactions (ORR). These Q3CTP-COF nanosheets show excellent ORR activity and potential for zinc-air batteries.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Metal-free carbon materials are crucial for oxygen reduction reactions (ORR) in clean energy.
- High density and accessibility of carbon active sites are key for efficient ORR catalysis.
Purpose of the Study:
- To synthesize novel quasi-three-dimensional cyclotriphosphazene-based covalent organic frameworks (Q3CTP-COFs) and their nanosheets.
- To evaluate their performance as electrocatalysts for ORR and in zinc-air batteries.
Main Methods:
- Synthesis of Q3CTP-COFs with abundant electrophilic structures.
- Exfoliation of bulk Q3CTP-COFs into thin nanosheets (NSs) via weak interlayer π-π interactions.
- Electrochemical testing of Q3CTP-COF NSs for ORR and application in Zn-air batteries.
Main Results:
- Q3CTP-COFs exhibit a high density of exposed carbon active sites due to their unique structure.
- Q3CTP-COF NSs demonstrate highly efficient ORR catalytic activity with a half-wave potential of 0.72 V vs. RHE.
- Q3CTP-COF NSs achieved a power density of 156 mW cm⁻² in Zn-air batteries.
Conclusions:
- The designed Q3CTP-COFs and their nanosheets are promising metal-free electrocatalysts for ORR.
- These materials offer a pathway for developing advanced catalysts for clean energy conversion technologies like Zn-air batteries.
