Promising priority separation of europium from lanthanide by novel DGA-functionalized metal organic frameworks

In this paper, a novel crystalline adsorbent MIL-101-DGA (DGA: Diglycolic Anhydride) is synthesized, which can change the order of traditional rare earth separation. This study is different from previously rare earth separation materials in which it can separate europium (III) first from other rare earth ions. The experiments result show that the separation coefficient (β) of preferentially separated europium (III) and other rare earth ions could reach 53.055, and the maximum adsorption capacity in the experiment was 33 mg/g. Density functional theory was used to calculate the absolute hardness of MIL-101-DGA from the perspective of hard-soft-acid-base theory, which explained the selective adsorption mechanism. Using MIL-101-DGA as an adsorbent, it can effectively recover Eu from the metal impurities Al, Ca, Cu, Mn, Zn and Y from the simulated phosphor leaching solution and has excellent recyclability. In summary, we believe that MIL-101-DGA is a new type of adsorbent that can effectively separate europium from rare earth and transition metal ions.