Iodine capture of a two-dimensional layered uranyl-organic framework: a combined DFT and AIMD study

To develop nuclear energy sustainably, it is important to effectively capture radioiodine in nuclear waste. In this study, we used density functional theory (DFT) and ab initio molecular dynamics (AIMD) calculations to investigate how well the uranyl-organic framework (UOF) could capture radioiodine. We found that the uranyl center and C-N ring sites in both cluster and periodic UOF models are very attractive to the I₂ molecule. The adsorption energies of the I₂ molecule in the periodic UOF models are as high as -1.10 eV, which is much higher than in the cluster model. The interaction characteristics between the I₂ molecule and the UOF were revealed by electronic density topological analyses. Our AIMD simulations at 300 and 600 K have confirmed that the UOF has high adsorption kinetics for I₂ molecules and can effectively capture them. The UOF has a high adsorption capacity and good adsorption stability for the I₂ molecule, making it a promising option for the environmentally friendly removal of radioiodine.