Attachment of Fe3O4 nanoparticles on UiO-66: A stable composite for efficient sorption and reduction of selenite from water
Kangchun Li, Jing Yang, Mingyuan Dou, Powei Gu, Haifeng Su, Fuchuan Huang
Abstract
In the present work, Fe3O4 nanoparticles were attached to the surface of UiO-66, a zirconium-based metal–organic framework material and the composite material formed was used to remove selenite (Se(IV)) in water. The Fe3O4/UiO-66 composite were assembled by a facile two-stage strategy. Benefiting from the ultra-high specific surface area of UiO-66, the Fe3O4/UiO-66 also had a large specific surface area, which made it easier to expose the active sites of Fe3O4 on the surface of UiO-66. The XPS and Mössbauer spectroscopy analysis indicated that there was charge transfer between Fe3O4 and UiO-66 in the Fe3O4/UiO-66, which made the Fe3O4 on the surface of UiO-66 had enhanced reductive activity. The mechanism of Fe3O4/UiO-66 to removed Se(IV) from the solution was further investigated by Zeta potential, FT-IR, SEM, TEM, and XPS spectra. The results indicated that the Fe3O4 nanoparticles on the surface of UiO-66 not only interacted with selenite through electrostatic action and inner-sphere complex but could also reduce a large amount of selenite to the insoluble Se0. The combination of these three actions finally strengthened the removal of selenite. This study cloud promote the practical application of MOF-based composites in removing heavy metal ions.