A pursuit to design highly sensitive fullerene-based sensors: adsorption and dissociation phenomenon of toxic sulfur gases on B40 fullerene.

Abstract

The adsorption phenomenon of toxic sulfur gases namely H2S and SO2 on B40 fullerene is scrutinized utilizing density functional theory-non-equilibrium Green's function (DFT-NEGF) regime. Adsorption of gas molecules is considered at both the hexagonal and heptagonal rings of the fullerene and adsorption energies, charge transfer, electron charge densities, density of states, transmission spectra, molecular energy spectra; Eigen states, HOMO-LUMO gap, current voltage curve, and differential conductance are premeditated. It is inferred that H2S molecule is physisorbed on the heptagonal ring of the fullerene while it is dissociative-chemisorbed on the hexagonal ring. SO2 dissociates into SO and O species on adsorption on both the hexagonal and heptagonal rings. From the transmission spectra and DOS analysis, LUMO dominant transmission is noticed in all the devices except the one formed with heptagonal ring adsorption of H2S which favors HOMO-dominated transmission. From the I-V curve and differential conductance investigation, different conductance values are noticed for all the junctions, thus proving that B40 is an efficient material to be engaged in sensing toxic sulfur gases.