Density functional theory investigation on the interaction of F2 with (4,0) SWCNT and X-doped (4,0) SWCNT for gas sensor application (X = B, S, Si, N, and Al)

Abstract

The interaction of B, S, Si, N, and Al-doped single-walled carbon nanotubes (SWCNT) clusters with Fluorine molecule (F 2 ) were investigated by using DFT method with B3LYP/6-31G(d,p) level of theory to assess their sensor abilities for detection of F 2 gas. This study has evaluated the adsorption energy, adsorption enthalpy, Gibbs free energy of adsorption, HOMO-LUMO energy gap, chemical potential, chemical hardness, global softness, electrophilicity, and sensitivity values. The results showed an exothermic and spontaneous interaction of F 2 with SWCNT and doped SWCNT, while the maximum negative adsorption energy values belong to Si-SWCNT. Si-SWCNT has the least HOMO-LUMO gap, chemical potential, and chemical hardness. It is softer than other dopant atoms and has good sensitivity as an F 2 gas sensor. Furthermore, the NBO analysis confirms that the highest interaction energies are related to Si-SWCNT with F 2 interaction. • F 2 adsorption on the pristine and (B, S, Si, N, Al)-doped SWCNT has been studied. • The F 2 adsorption energy order was pristine < N- < S- < B- < Al- < Si-doped SWCNT. • Intermolecular charge transfer was present on the interaction of F 2 with all SWCNT. • Si-SWCNT has the lowest HOMO-LUMO gap, chemical potential, and chemical hardness.