Structural Engineering of Covalent Organic Frameworks Comprising Two Electron Acceptors Improves Photocatalytic
Jin Zhang1, Yuping Cao1, Wei Liu2
1College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, P. R. China.
Chemsuschem
|November 9, 2021
Summary
Introducing dual acceptors, triazine and ketone, in covalent organic frameworks (COFs) significantly boosts photocatalytic hydrogen production by enhancing charge separation. Optimizing acceptor distance further improves efficiency.
Area of Science:
- Materials Science
- Photocatalysis
- Green Chemistry
Background:
- Covalent organic frameworks (COFs) are emerging as promising photocatalysts for sustainable hydrogen production.
- Efficient separation of photogenerated electron-hole pairs is crucial for improving COF photocatalytic activity.
Purpose of the Study:
- To investigate the impact of simultaneous triazine and ketone acceptors on electron-hole separation in COFs.
- To explore how the distance between acceptors affects photocatalytic hydrogen production efficiency.
Main Methods:
- Synthesis of four COFs via Schiff-base reactions with varying acceptor configurations.
- Photocatalytic hydrogen production rate measurements.
- Systematic variation of acceptor distance using biphenyl linkers.
Main Results:
- COFs with simultaneous triazine and ketone acceptors exhibited superior electron-hole separation efficiency.
- The COF containing both acceptors showed the highest hydrogen production rate (31.43 μmol h⁻¹), significantly outperforming COFs with single acceptors.
- A single phenyl group as a transport linker between acceptors proved most favorable for photocatalysis.
Conclusions:
- Simultaneous presence of triazine and ketone acceptors in COFs enhances charge separation and photocatalytic activity.
- Optimizing the spatial arrangement and distance between acceptors is critical for designing efficient COF photocatalysts.
- This study provides valuable insights for developing advanced COF materials for hydrogen production.
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