Yuan Liu1,An Ta1,Shubham Pandey1,2,Shenyang Hu3,Natalia Shustova4,Simon Phillpot1
University of Florida1,Colorado School of Mines2,Pacific Northwest National Laboratory3,University of South Carolina4
Yuan Liu1,An Ta1,Shubham Pandey1,2,Shenyang Hu3,Natalia Shustova4,Simon Phillpot1
University of Florida1,Colorado School of Mines2,Pacific Northwest National Laboratory3,University of South Carolina4
Zr-based metal-organic frameworks (Zr-MOFs) have been widely used as ion absorbents for the removal or extraction of toxic and/or radionuclide species from aqueous solutions. However, the mechanisms by which uranyl ions interact with the Zr-MOFs have not been established. Here, the nature of the bonding of a uranyl ion (22+) with a Zr-MOF was determined using density functional theory for nineteen structurally distinct candidate complexes. The results showed that the uranyl ions bond to Zr-MOF with binding energies of the order of 1.5 eV. In the energetically most favorable structure, this strong adsorption is achieved by the formation of bonds between the uranyl ion with one middle oxygen and one edge oxygen in the Zr-MOF metal node. It was also found that the higher the degree of deprotonation of Zr-MOF, the higher the binding energy between Zr-MOF and uranyl ions.<br/>This work was supported by the Center for Hierarchical Waste Form Materials (CHWM), an Energy Frontier Research Center (EFRC) funded by the United States Department of Energy Office of Basic Energy Sciences through Award DESC0016574.