Highly Selective Recovery of Lanthanides by Using a Layered Vanadate with Acid and Radiation Resistance

It is of vital importance to capture lanthanides (nuclear fission products) from waste solutions for radionuclide remediation owing to their hazards. The effective separation of lanthanides are achieved by an acid/base-stable and radiation-resistant vanadate, namely, [Me₂ NH₂ ]V₃ O₇ (1). It exhibits high adsorption capacities for lanthanides (q_m ^Eu =161.4 mg g^-1 ; q_m ^Sm =139.2 mg g^-1 ). And high adsorption capacities are maintained over a pH range of 2.0-6.9 (q_m ^Eu =75.1 mg g^-1 at low pH of 2.5). It displays high selectivity for Eu³⁺ (simulant of An³⁺ ) against a large excess of interfering ions. It can efficiently separate Eu³⁺ and Cs⁺ (or Sr²⁺ ) with the highest separation factor SF_Eu/Cs of 156 (SF_Eu/Sr of 134) to date. The adsorption mechanism is revealed by calculations and XPS, EXAFS, Raman, and elemental analyses. These merits combined with facile synthesis and convenient elution makes the title vanadate a promising lanthanide scavenger for environmental remediation.