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Abstract The first synthesis and comprehensive characterization of two vinyl tetrazine‐linked covalent organic frameworks (COF), TA‐COF‐1 and TA‐COF‐2, are reported. These materials exhibit high crystallinity and high specific surface areas of 1323 and 1114 m2g−1. The COFs demonstrate favorable band positions and narrow band gaps suitable for light‐driven applications. These advantages enable TA‐COFs to act as reusable metal‐free photocatalysts in the arylboronic acids oxidation and light‐induced coupling of benzylamines. In addition, these TA‐COFs show acid sensing capabilities, exhibiting visible and reversible color changes upon exposure to HCl solution, HCl vapor, and NH3vapor. Further, the TA‐COFs outperform a wide range of previously reported COF photocathodes. The tetrazine linker in the COF skeleton represents a significant advancement in the field of COF synthesis, enhancing the separation efficiency of charge carriers during the photoreaction and contributing to their photocathodic properties. TA‐COFs can also degrade 5‐nitro‐1,2,4‐triazol‐3‐one (NTO), an insensitive explosive present in industrial wastewater, in 20 min in a sunlight‐driven photocatalytic process; thus, revealing dual functionality of the protonated TA‐COFs as both photodegradation and Brønsted acid catalysts. This pioneering work opens new avenues for harnessing the potential of the tetrazine linker in COF‐based materials, facilitating advances in catalysis, sensing, and other related fields.
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Viologen‐Derived Covalent Organic Frameworks: Advancing PFAS Removal Technology with High Adsorption Capacity
Abstract The escalating presence of per‐ and polyfluoroalkyl substances (PFAS) in drinking water poses urgent public health concerns, necessitating effective removal. This study presents a groundbreaking approach, using viologen to synthesize covalent organic framework nanospheres: MELEM‐COF and MEL‐COF. Characterized by highly crystalline features, these nanospheres exhibit exceptional affinity for diverse anionic PFAS compounds, achieving simultaneous removal of multiple contaminants within 30 min. Investigating six anionic PFAS compounds, MEL‐ and MELEM‐COFs achieved 90.0–99.0% removal efficiency. The integrated analysis unveils the synergistic contributions of COF morphology and functional properties to PFAS adsorption. Notably, MELEM‐COF, with cationic surfaces, exploits electrostatic and dipole interactions, with a 2500 mg g−1adsorption capacity—surpassing all reported COFs to date. MELEM‐COF exhibits rapid exchange kinetics, reaching equilibrium within 30 min. These findings deepen the understanding of COF materials and promise avenues for refining COF‐based adsorption strategies.
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- Award ID(s):
- 1719875
- PAR ID:
- 10531891
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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