A knot-linker planarity control strategy for constructing highly crystalline cationic covalent organic frameworks: decoding the effect of crystallinity on adsorption performance. Issue 25 (17th June 2020)

• Record Type: Journal Article
• Authors: Da, Hong-Ju; Yang, Cheng-Xiong; Qian, Hai-Long; Yan, Xiu-Ping
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 25(2020)
• Page Start: 12657
• Page End: 12664
• Publication Date: 2020-06-17
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta01037e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A knot-linker planarity control strategy was developed to construct highly crystalline cationic covalent organic frameworks with C3-symmetric guanidine units for fast removal of 2, 4-dichlorophenol with high adsorption capacity. Abstract : Ionic covalent organic frameworks (iCOFs), a subclass of COFs, offer a functional platform for diverse applications. However, strong charge repulsion between adjacent layers often leads to low-crystalline iCOFs. Herein, we report a knot-linker planarity control strategy to synthesize a highly crystalline iCOF with C3-symmetric cationic units. More planarity of building blocks gives higher crystallinity of iCOFs, leading to a larger surface area and more exposed binding sites of iCOFs. The highly crystalline iCOF in turn gives larger uptake capacity and faster kinetics than the low-crystalline iCOF and the non-crystalline iCOF, uncovering the significance of crystallinity for the removal of pollutants. The prepared highly crystalline TFPT–TGCl –iCOF exhibits larger saturation sorption capacity (893 mg g −1 ) than previous adsorbents for 2, 4-dichlorophenol. The developed strategy provides a new way to construct highly crystalline iCOFs with C3 symmetric-type cationic sites for various applications.