Tuning Local Charge Distribution in Multicomponent Covalent Organic Frameworks for Dramatically Enhanced Photocatalytic Uranium Extraction |
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Authors: | Hui Yang Mengjie Hao Yinghui Xie Xiaolu Liu Yanfang Liu Zhongshan Chen Xiangke Wang Geoffrey I N Waterhouse Shengqian Ma |
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Institution: | 1. College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206 P.R. China;2. School of Chemical Sciences, The University of Auckland, Auckland, 1142 New Zealand;3. Department of Chemistry, University of North Texas, Denton, TX-76201 USA |
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Abstract: | Optimizing the electronic structure of covalent organic framework (COF) photocatalysts is essential for maximizing photocatalytic activity. Herein, we report an isoreticular family of multivariate COFs containing chromenoquinoline rings in the COF structure and electron-donating or withdrawing groups in the pores. Intramolecular donor-acceptor (D-A) interactions in the COFs allowed tuning of local charge distributions and charge carrier separation under visible light irradiation, resulting in enhanced photocatalytic performance. By optimizing the optoelectronic properties of the COFs, a photocatalytic uranium extraction efficiency of 8.02 mg/g/day was achieved using a nitro-functionalized multicomponent COF in natural seawater, exceeding the performance of all COFs reported to date. Results demonstrate an effective design strategy towards high-activity COF photocatalysts with intramolecular D-A structures not easily accessible using traditional synthetic approaches. |
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Keywords: | Charge Distribution Covalent Organic Frameworks Donor-Acceptor Photocatalysis Post-Synthesis |
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