Highly efficient extraction of uranium from seawater by polyamide and amidoxime co-functionalized MXene.

Uranium mainly exists in the form of uranyl carbonate in seawater. [UO 2 (CO 3) 3 ]^4- has strong stability, which increases the difficulty of uranium extraction from seawater. Meanwhile, the complex marine environment, a large number of coexisting competing ions and biological pollution are all non-negligible disturbing factors. Herein, we introduced amidoxime (AO) groups into the surface of Ti 3 C 2 and grafted polyamides (PA) by a simple one-step hydrothermal method to produce an efficient seawater uranium extraction adsorbent Ti 3 C 2 -AO-PA. Owing to the amidoxime groups, the material was highly selective for uranium. And the large number of amino groups in the polyamides gave it ideal resistance to biofouling. The possibility of Ti 3 C 2 -AO-PA as an adsorbent for uranium extraction from seawater was confirmed by various characterization techniques, numerous adsorption batch experiments, simulated seawater experiments and antibacterial performance tests. It was demonstrated that the uptake of [UO 2 (CO 3) 3 ]^4- by Ti 3 C 2 -AO-PA showed fast reaction kinetics (about 120 min), brilliant absorption capacity (81.1 mg·g⁻¹ at pH 8.3), significant high selectivity (32.8 mg-U/g-Ads) and outstanding anti-biological contamination performance (92.9% antibacterial rate). XPS and DFT further indicated that the high extraction ability of Ti 3 C 2 -AO-PA for uranium was mainly attributed to the strong complexation of AO and –NH 2 with [UO 2 (CO 3) 3 ]^4-. These conclusions showed that Ti 3 C 2 -AO-PA not only had an ideal application prospect for uranium extraction from seawater, but also provided an available strategy for rapid and selective uranium adsorption from real seawater. [Display omitted] • Polyamide enhanced amidoxime-functionalized Ti 3 C 2 nanosheet was constructed. • The uranium extraction capacity was highly enhanced. • Ti 3 C 2 -AO-PA showed excellent selectivity and antimicrobial properties. • Synergistic interactions of amidoxime and polyamide with uranium ions in seawater. [ABSTRACT FROM AUTHOR]