Endohedral and Exohedral adsorption of helium on X12N12 (X = B, Al) nano-cluster: A DFT study

The behavior of noble gas (such as helium) adsorption inside and outside the B12N12 and Al12N12 was investigated within density functional theory calculations. In the case of inside encapsulation, both clusters have endothermic reactivity with helium which shows from standpoint of stability, helium encapsulation in these cages is not favorable. But, for exohedral functionalization of clusters with He, B12N12 was good candidate. The most stable adsorption site found to be atop the boron atom of the cluster surface with adsorption energy of -1.29 eV. We predict that in outside of cluster each boron atom in a B12N12 can adsorb one He molecules.