Selective extraction of uranium from seawater on amidoximated MXene/metal-organic framework architecture under an electric field

Abstract

Seawater holds tremendous uranium resources, which can sustain the global nuclear industry for thousands of years. However, the existing technologies for uranium extraction from seawater (UES) are constrained by the ultra-low uranium concentration and high interference background. A three-dimensional amidoximated Ti3C2Tx/ZIF-67 architecture (TAZ) is fabricated for highly efficient uranium capture via electrosorption. Besides the excellent electrical conductivity of Ti3C2Tx, the introduction of amidoxime groups and ZIF-67 nanoparticles endows TAZ with porous structure and abundant active sites, which favors the rapid uranyl ions diffusion and enhanced electrosorption. TAZ displays a remarkable uranium extraction uptake of 2224.54 mg/g under an applied voltage of 1 V. Meanwhile, TAZ possesses prominent uranium selectivity resulting from amidoxime groups and imidazole N. TAZ also maintains a good reusability of 63.51% after 10 cycles. Furthermore, the bactericidal rates of TAZ against both Escherichia coli and Staphylococcus aureus achieve nearly 100%. The excellent properties have made TAZ apt for UES with a high uranium uptake of 11.40 mg/g in 24 h under an electric field, which is 5.3 times higher than the physicochemical adsorption. Our work provided a strategy to design high-performance nanomaterials for efficient uranium mining from seawater.