3D hierarchical porous amidoxime fibers speed up uranium extraction from seawater†
The development of amidoxime-based polymeric (ABP) fibers offers a solution for uranium extraction from seawater (UES) and provides an alternative solution to the uranium resource shortage. However, ABP adsorbents prepared by existing methods cannot meet the requirements of high adsorption capacity, high selectivity, good mechanical strength and long service life. Herein, we fabricated a 3D hierarchical porous, high specific surface area ABP (H-ABP) fiber via self-assembly of axial grafting chains. A high adsorption capacity of 11.50 mg-U per g-adsorbents was achieved in natural seawater, which is a significant breakthrough in UES. Meanwhile, the adsorption capacity of uranium was higher than its major competing element vanadium, which overturned the U/V mass ratio of the ABP fiber. The H-ABP fiber also exhibited good mechanical strength and a long service life of at least 10 adsorption–desorption cycles. The well-designed structure resulted in groundbreaking properties, which completely meet the requirements for the economic evaluation of UES. This work presents a new technology for the synthesis of highly efficient adsorbents for UES, thus opening a whole new means of nuclear fuel production from the ocean.