Layered double hydroxide intercalated with dimethylglyoxime for highly selective and ultrafast uptake of uranium from seawater

In this study, we demonstrate the first example of a MgAl layered double hydroxide intercalated by a ketoxime compound (dimethylglyoxime, DMG), that is, MgAl-DMG-LDH (abbr. DMG-LDH), which exhibits excellent capture of uranium (U(vi)) both at high (ppm) and low (ppb) concentrations. The as-formed DMG-LDH shows an enormous maximum U(vi) sorption capacity (qU(m)) of 380 mg g(-1) and an exceptionally rapid sorption rate (k(2) = 2.97 g mg(-1) min(-1)), reaching a high uptake of 99.14% within 5 min. For natural and contaminated seawater with high concentrations of Na+, Ca2+, Mg2+ and K+ concomitant cations, the DMG-LDH still can trap similar to 85% U, displaying highly effective sorption toward U. The interaction mechanism between UO22+ and DMG(2-) provides an important reference for the development of highly effective capture of U(vi) by ketoxime materials. The DMG-LDH is currently the best ketoxime material for uranium extraction from nuclear waste and seawater.