"Ion-imprinting" strategy towards metal sulfide scavenger enables the highly selective capture of radiocesium.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38769121.
- Also identified by DOI 10.1038/s41467-024-48565-x and PMC identifier 11106286.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Highly selective capture of radiocesium is an urgent need for environmental radioactive contamination remediation and spent fuel disposal. Herein, a strategy is proposed for construction of "inorganic ion-imprinted adsorbents" with ion recognition-separation capabilities, and a metal sulfide Cs<sub>2.33</sub>Ga<sub>2.33</sub>Sn<sub>1.67</sub>S<sub>8</sub>·H<sub>2</sub>O (FJSM-CGTS) with "imprinting effect" on Cs<sup>+</sup> is prepared. We show that the K<sup>+</sup> activation product of FJSM-CGTS, Cs<sub>0.51</sub>K<sub>1.82</sub>Ga<sub>2.33</sub>Sn<sub>1.67</sub>S<sub>8</sub>·H<sub>2</sub>O (FJMS-KCGTS), can reach adsorption equilibrium for Cs<sup>+</sup> within 5 min, with a maximum adsorption capacity of 246.65 mg·g<sup>-1</sup>. FJMS-KCGTS overcomes the hindrance of Cs<sup>+</sup> adsorption by competing ions and realizes highly selective capture of Cs<sup>+</sup> in complex environments. It shows successful cleanup for actual <sup>137</sup>Cs-liquid-wastes generated during industrial production with removal rates of over 99%. Ion-exchange column filled with FJMS-KCGTS can efficiently treat 540 mL Cs<sup>+</sup>-containing solutions (31.995 mg·L<sup>-1</sup>) and generates only 0.12 mL of solid waste, which enables waste solution volume reduction. Single-crystal structural analysis and density functional theory calculations are used to visualize the "ion-imprinting" process and confirm that the "imprinting effect" originates from the spatially confined effect of the framework. This work clearly reveals radiocesium capture mechanism and structure-function relationships that could inspire the development of efficient inorganic adsorbents for selective recognition and separation of key radionuclides.