Theoretical Study of Li, Si, and Sn Adsorption on Single-Walled Boron Nitride Nanotubes

The adsorption of Si, Sn, and Li on single-walled boron nitride nanotubes has been studied by density functional theory calculation. Both single Si or Sn atoms and their dimers are able to adsorb on the outer surface of (8,0) BNNT exothermically. The adsorption of dimers is weaker than that of a single atom. With increasing the tube diameter from (8,0) to (16,0), the adsorption energy of a single atom decreases slightly. The adsorption of single Si and Sn atoms induces magnetism whereas dimers do not. None of the single adatoms or dimers is stable inside the (8,0) BNNT. Except for a single Li atom, all other single adatoms and dimers are stable inside (12,0) BNNT with an adsorption energy of less than −0.4 eV. The alloying of a Li atom with Si or Sn further stabilizes the system, showing that BNNTs encapsulated Si or Sn might be a potential Li storage material.