A case study for the uranyl recovery over magnetically retrievable Cu-BTC@Fe 3 O 4 nanocomposites

A magnetic Metal–Organic Framework (MOF) nanocomposite, namely Cu-BTC@Fe 3 O 4 (BTC = 1,3,5-benzenetricarboxylate) was used for magnetically retrievable separation of uranyl (UO 2 2+ ) in the presence of competitive ions. A significant adsorption amount of 312 mg/g was achieved for uranium over Cu-BTC@Fe 3 O 4 at a pH value of 4.5. Extended X-ray Absorption Fine Structure (EXAFS) analysis indicated that the interaction of Cu-BTC@Fe 3 O 4 with UO 2 2+ is the synergistic coordination of carboxylate groups of BTC ligand, Fe 3 O 4 -COOH, and hydrate H 2 O for UO 2 2+ ions. In addition to identifying a stable and retrievable adsorbent, the results generally elucidate UO 2 2+ removal of MOFs composites.