Highly hydrophilic covalent organic frameworks as efficient and reusable photocatalysts for oxidative coupling of amines in aqueous solution. Issue 9 (24th March 2022)

• Record Type: Journal Article
• Authors: Liu, Shufang; Su, Qing; Qi, Wei; Luo, Kexin; Sun, Xiaoman; Ren, Hao; Wu, Qiaolin
• Is Part Of: Catalysis science & technology. Volume 12:Issue 9(2022)
• Page Start: 2837
• Page End: 2845
• Publication Date: 2022-03-24
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/d2cy00167e
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : Highly hydrophilic 2D-COFs, TFB-XX-DMTH, have been successfully constructed by a three-component in situ assembly strategy and exhibited superior photocatalytic performance in oxidative coupling reactions of benzylamines in aqueous solution. Abstract : As a class of new emerging crystalline porous materials, photoactive covalent organic frameworks (COFs) have exhibited great potential for photocatalytic applications for metal-free organic transformations. In this study, we report three hydrophilic two-dimensional (2D) COFs achieved by a polycondensation reaction of 2, 5-dimethoxyterephthalohydrazide (DMTH ), 1, 3, 5-triformylbenzene (TFB ) and 2-hydroxy-1, 3, 5-benzenetricarbaldehyde (SOH ) under solvothermal conditions. The resulted COF materials, TFB-XX-DMTH (XX = 33, 50 and 66, corresponding to a molar ratio of TFB/SOH = 1 : 2, 1 : 1, and 2 : 1), are successfully constructed by a three-component in situ assembly strategy and thus exhibit high crystallinity, large surface areas (up to 1808 m 2 g −1 ) and good thermal and chemical stability. Moreover, benefiting from the enhanced charge separation efficiency and high hydrophilicity, the TFB-XX-DMTH materials could be employed as photocatalysts for visible-light-driven oxidative coupling reactions of benzylamines in aqueous solution. The photocatalytic performance with high conversion, selectivity and recyclability could be attributed to a combined result of efficient generation, migration and separation of photogenerated carriers in such a platform. Our results provide insights into the structure–function correlation of COF photocatalysts and also highlight their potential in developing photofunctional COFs for sustainable organic transformations.