Adsorption properties of BF4- anions on graphene

We theoretically have been investigating the basic adsorption properties of BF4- anions on graphene as the first step in researching the properties of carbon nanotube (CNT) electrodes in an electric double layer capacitor. To clarify the basic adsorption properties, we used the first principles calculation based on the density functional theory with the generalized gradient approximation for the exchange–correlation energy. As for the results, we found that the adsorbed configuration of BF4- anions on graphene changes as their nearest neighbor distance decreases. We show that the electric dipole moment per unit area of BF4- adsorbed on graphene increases as the nearest neighbor anion distance decreases. On the other hand, the electric dipole moment per BF4- anion decreases as the nearest anion neighbor distance decreases. We also found that BF4- anions adsorbed on both sides of graphene are more stable than those on one side