Computational studies on chemically engineered carbon nanotubes as HCl sensor

Abstract

The effect of functionalization on the sensing properties of a single-walled carbon nanotube in terms of work function and HOMO-LUMO gap changes has been studied by using density functional calculations. Our findings explain the experimental data on the electrical behavior of the SWNTs upon HCl adsorption. Protonation of the basic group induces an electron transfer from the semiconducting SWNTs, thereby altering the HOMO and LUMO levels and significantly changing the electronic properties and work function. The performance of the pyridinol functionalized SWNT as an HCl gas sensor is shown to be superior to the other studied materials, in terms of both response signal and reversibility time. These results are in good agreement with the experimental reports.