Fluorine and chlorine gas storage by confinement inside boron nitrogen nanotubes

DFT calculations using the WB97XD and CAM-B3LYP functional and the basis set 6-31G(d,p) have been performed to study the interaction between the X-2 (X=F or Cl) molecule and boron nitrogen nanotubes (BNNTs). Each molecule is confined within BNNTs with different dimensions in either parallel or perpendicular positions along the nanotube axis. The interaction between X-2 molecule and BNNT nanotube differed according to the extension of the confinement space and the molecular orientation. Unlike Cl-2, F-2 forms a very stable complex with (4,4) and (5,5) BNNTs. The van der Waals interactions of the X-2 molecule with the BNNT leads to charge transfer and a change in the charge distribution in the X-2 molecule, producing a new detectable infrared signal of the X-X bond stretch which is dependent on nanotube diameter.