Highly Selective Recovery of Lanthanides by a Facilely-Synthesized Layered Vanadate with Acid and Radiation Resistance.

Abstract

It is of vital importance to capture lanthanides\xa0(nuclear\xa0fission products)\xa0from waste solutions for radionuclide remediation\xa0due to their hazards.\xa0Herein the effective separation of lanthanides\xa0are achieved by an acid/base-stable and radiation-resistant vanadate,\xa0namely,\xa0[Me2NH2]V3O7\xa0(1). It exhibits high adsorption capacities\xa0for lanthanides (e. g., qmEu\xa0= 161.4\xa0mg/g;\xa0qmSm\xa0= 139.2\xa0mg/g).\xa0And high adsorption\xa0capacities\xa0are maintained over\xa0a pH\xa0range\xa0of 2.0 -\xa06.9 (e. g., qmEu\xa0=\xa075.1 mg/g\xa0at low pH of\xa02.5). It\xa0displays high selectivity\xa0for Eu3+\xa0(simulant of An3+) against a large excess\xa0of interfering ions. Particularly, it can efficiently\xa0separate Eu3+\xa0and\xa0Cs+\xa0(or\xa0Sr2+) with the highest separation factor\xa0SFEu/Cs\xa0of 156 (SFEu/Sr\xa0of 134) to date. The adsorption mechanism is revealed by theoretical calculations\xa0coupled with characterizations of XPS, EXAFS, Raman and elemental analyses.\xa0These merits combined with\xa0facile synthesis and convenient\xa0elution makes\xa0the title vanadate\xa0a\xa0promising lanthanide\xa0scavenger for environmental remediation.