Design and Fabrication of Hypercrosslinked Covalent Organic Adsorbents for Selective Uranium Extraction

Economicallystable PAE-based COP materials for efficienton-site detection and extraction of uranium in water. Uraniumdetection and extraction are necessary for the ecologicalenvironment as the growing demand for nuclear energy. Hence, exploringstable materials with excellent performance in uranium extractionand detection is highly desired. Herein, by amidoxime-functionalizingtetrafluoroterephthalonitrile (TFTPN) crosslinked hydroquinone (bP),phloroglucinol (tP), and 4,4 & PRIME;,4 & DPRIME;-trihydroxytriphenylmethane(tBP), three covalent organic polymers (COPs) bPF-AO, tPF-AO, and tBPF-AO with different crosslinkedarchitectures are fabricated. Uranium extraction and detection relatedto the difference in molecule construction were systemically investigated,giving some reference for the rational design and fabrication of advancedmaterials for the removal and monitoring of uranium in the environment.The tPF-AO with a compact steric structure achieves thehighest theoretical maximum adsorption capacity of 578.9 & PLUSMN; 15.2mg g(-1) and the best recyclability. The scatteringelectron center and U(VI) selective binding sites endow tBPF-AO with excellent capability in selective detection for U(VI), witha limit of detection of 24.2 nmol L-1, which iswell below the standard for U(VI) in drinking water of the World HealthOrganization (WHO). Moreover, the COPs possess prominent physicochemicalstability and recyclability, and more importantly, the PAE-based COPsare derived from inexpensive industry materials with easy processingmethods, providing an efficient and economical way for the detectionand adsorption of uranium.