Anchoring ZIF-67 particles on amidoximerized polyacrylonitrile fibers for radionuclide sequestration in wastewater and seawater

Capturing uranium (U(VI)) ions from wastewater and seawater is highly attractive for the environment and clean energy with the increasing deficiency of land sources. Howbeit, the massive volume of water and the ultralow concentration of U(VI) pose a substantial challenge to the industrial application. Accordingly, we have synthesized a novel organic-inorganic hybrid adsorbent through in-situ growing MOF particles on electrospun polyacrylonitrile fibers (PAN) followed by modifing with amidoxime groups to form amidoximed PAN/ZIF-67 (AOPAN/ZIF) hybrid fibers. In such fibers, the N atoms from imidazole and amidoxime can improve the adsorption performance synergistically in a wide pH range, which is favorable for capturing U(VI) under nuclear wastewater and seawater. As a result, the AOPAN/ZIF fibers exhibit high adsorption amount of 498.4 mg g(-1) in U(VI) contaminated aqueous solution at pH 4. Furthermore, the adsorption amount of U(VI) reached 2.03 mg g(-1) in natural seawater after 36 d, which implies that the AOPAN/ZIF fibers may promote the development of U(VI) recovery.