Efficient Uranium Capture by Polysulfide/Layered Double Hydroxide Composites

Shulan Ma, Lu Huang, Lijiao Ma, Yurina Shim, Saiful M. Islam, Pengli Wang, Li Dong Zhao, Shichao Wang, Genban Sun, Xiaojing Yang, Mercouri G. Kanatzidis

Research output: Contribution to journalArticlepeer-review

234 Citations (Scopus)


There is a need to develop highly selective and efficient materials for capturing uranium (normally as UO22+) from nuclear waste and from seawater. We demonstrate the promising adsorption performance of Sx-LDH composites (LDH is Mg/Al layered double hydroxide, [Sx]2- is polysulfide with x = 2, 4) for uranyl ions from a variety of aqueous solutions including seawater. We report high removal capacities (qm = 330 mg/g), large KdU values (104-106 mL/g at 1-300 ppm U concentration), and high % removals (>95% at 1-100 ppm, or ∼80% for ppb level seawater) for UO22+ species. The Sx-LDHs are exceptionally efficient for selectively and rapidly capturing UO22+ both at high (ppm) and trace (ppb) quantities from the U-containing water including seawater. The maximum adsorption coeffcient value KdU of 3.4 × 106 mL/g (using a V/m ratio of 1000 mL/g) observed is among the highest reported for U adsorbents. In the presence of very high concentrations of competitive ions such as Ca2+/Na+, Sx-LDH exhibits superior selectivity for UO22+, over previously reported sorbents. Under low U concentrations, (S4)2- coordinates to UO22+ forming anionic complexes retaining in the LDH gallery. At high U concentrations, (S4)2- binds to UO22+ to generate neutral UO2S4 salts outside the gallery, with NO3- entering the interlayer to form NO3-LDH. In the presence of high Cl- concentration, Cl- preferentially replaces [S4]2- and intercalates into LDH. Detailed comparison of U removal efficiency of Sx-LDH with various known sorbents is reported. The excellent uranium adsorption ability along with the environmentally safe, low-cost constituents points to the high potential of Sx-LDH materials for selective uranium capture.

Original languageEnglish
Pages (from-to)3670-3677
Number of pages8
JournalJournal of the American Chemical Society
Issue number10
Publication statusPublished - Mar 18 2015

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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