Theoretical screening of single-atom doped M-N4-graphene for the efficient captures of fission gas Xe

It is highly important to develop the technology for the adsorption and separation of fission gases in the fields of nuclear environment monitoring and spent fuel disposal. The adsorption behaviors of fission gas Xe on a series of single-metal-atom doped N ₄-graphene (N ₄-G) were investigated with density functional theory (DFT) calculations in this work. The metal (M) atoms can be robustly anchored by the N-doped graphene (N ₄-G) in single-atom form rather than clustering together. The M-N bonds with the high-degree covalent nature account for the high binding energy of N ₄-G for single-metal-atom.The Sc-N ₄-G and Ti-N ₄-G with fairly low adsorption energy for Xe were screened out as efficient adsorbents from seventeen kinds of M-N ₄-G species studied. The high-degree charge redistribution in the Xe adsorption process is responsible for their high affinity for Xe. The Hirshfeld charge of adsorbed Xe on M-N ₄-G shows a high linear correlation with adsorption energy. Our study would provide useful insights into the potential applications of single-atom doped N ₄-graphene in the management of fission gases.