Core-shell hierarchical C@Na2Ti3O7 center dot 9H(2)O nanostructures for the efficient removal of radionuclides

Titanate nanostructures are promising materials for their far superior performance in the uptake and immobilization of radioactive cations from wastewater. In this study, core-shell sodium titanate hierarchical nanostructures (C@Na2Ti3O7 center dot 9H(2)O, CSTHNs) were fabricated through a combination method (chemical deposition and hydrothermal reaction). The Brunauer-Emmett-Teller (BET) surface area of the CSTHNs is as high as 205.3 m(2) g(-1). CSTHNs show high removal capacities (Q(max) = 5.757 mmol g(-1), 8.151 mmol g(-1) and 4.846 mmol g(-1)) and large K-d values (10(3)-10(4) mL g(-1)) for Cs+, UO22+ and Eu3+ species. The ion exchange and inner-sphere complexation are used to explain the ability of CSTHNs to capture radioactive ions. The influence of valence, hardness and radius of cations on the ion exchange process and complexation are also discussed. The structural collapse of the CSTHNs and the irreversible entrapment of the radioactive cations were confirmed. These results indicate that target radionuclides are efficiently concentrated from water and tightly immobilized in the interlayer which is of great significance for the removal and subsequent safe disposal of hazardous radionuclides. This approach may be helpful for the design and fabrication of high performance adsorbents, and may be widely applied in pollution treatments.