High-Performance Metal-Organic Framework-Templated Sorbent for Selective Eu(III) Capture

Abstract

A stable porous sorbent M1 was achieved through the specific transformation of flexible thioalkyl groups and metal cluster sites in a zirconium MOF (metal-organic framework; Zr-L) template. The target polymer combines sulfoxide/sulfone and phosphoric acid in a single framework, which was fully characterized by 1H-NMR, PXRD, IR, and elemental analysis. When employed as the heavy metal adsorbent, M1 exhibit a remarkable Eu(III) sorption behavior, achieving both high chemical affinity (Kd = 105) and sorption capacity (the maximum Eu(III) sorption capacity reached 220 mg g-1 at pH = 4.0 and T = 298 K calculated from the Langmuir model). Recyclability and selectivity test of M1 further prove that the sorbent is highly stable and effective for europium enrichment in the aqueous solution. This work takes focus on the introduction of multifunctional groups into a single polymeric framework in a feasible and environmentally friendly way and highlights the sorption efficiency for europium removal from the aqueous solution.