Polysulfide grafted with hydrophilic group for efficient capture of uranium (VI) from water

Efficient capture of uranium (VI) from wastewater holds great importance for environmental remediation and sustainable development of nuclear energy. Herein, polysulfide PS-HEA-X with grafted hydrophilic groups was fabricated as an efficient adsorbent for the capture of uranium (VI) in water by using 2-hydroxyethyl acrylate (HEA) as a hydrophilic regulator. The practical maximum uranium (VI) adsorption capacity of hydrophilic PS-HEA-20 reached 638.29 mg/g, which was about 24 times that of hydrophobic PS-HEA-0 synthesized without HEA modifier. The uranium (VI) adsorption capacity of PS-HEA-20 per unit surface area reached 124.42 mg/m 2 , which outperformed most reported absorbents. Structure-performance relations indicated that the grafted –OH, –COO- groups improved the hydrophilicity of PS-PEA-20, hereby facilitating the diffusion of uranium (VI) in solution to the surface of PS-PEA-20. Adsorption mechanism investigation results showed that UO 2 2+ were captured by the surface S atoms of PS-HEA-20 through soft acids-soft base interaction. PS-HEA-20 exhibited excellent reusability and the adsorption capacity remains higher than 90 % after five cycles using Na 2 CO 3 solution as eluent. This work not only expands the application of S-based polymer for efficient capture of uranium (VI) from water, but also offers a facile strategy for the fabrication of polysulfide for the capture of uranium (VI) and other heavy metal ions.