Binding of uranyl cations to a Zr-based metal-organic framework by density functional theory

• Published in: Computational materials science 2023-10, Vol.230, p.112528, Article 112528
• Main Authors: Liu, Yuan, Ta, An T., Pandey, Shubham, Chul Park, Kyoung, Hu, Shenyang, Shustova, Natalia B., Phillpot, Simon R.
• Format: Article
• Language: English
• Subjects: Density functional theory; MATERIALS SCIENCE; Metal-organic frameworks; Uranyl cation; Zr-MOF
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2023.112528

We used density functional theory to simulate the binding behavior of uranyl cation attaching on the Zr-MOF metal node. [Display omitted] Zr-based metal–organic frameworks (Zr-MOFs) have been widely used as ion adsorbents for the removal or extraction of toxic and/or radionuclide species from aqueous solutions. However, the mechanisms by which uranyl cations (UO22+) interact with Zr-MOFs have not been established. In this work, the nature of the bonding of uranyl cations with a Zr-MOF was determined using density functional theory for nineteen structurally distinct candidate complexes. The results showed that in all cases the binding energy was of the order of 1.5 eV, but depended on the specific bonding site. The most stable structure involved coordination of the uranyl cation and two structurally distinct oxygens in the Zr-MOF metal node. It was also found that higher degree of deprotonation in Zr-MOF correlated with higher binding energy between the Zr-MOF and uranyl cations. These insights can aid in the design of Zr-MOFs with optimized features for efficient capture of uranyl cations.