TITLE:
Effect of Tubular Chiralities and Diameters of Single Carbon Nanotubes on Gas Sensing Behavior: A DFT Analysis
AUTHORS:
A. A. EL-Barbary, Kh. M. Eid, M. A. Kamel, H. M. Osman, G. H. G. H. Ismail
KEYWORDS:
Carbon Nanotubes, DFT, Gas Sensors
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.4 No.2,
April
18,
2014
ABSTRACT: Using density functional
theory, the adsorption of CO, CO2, NO and CO2 gas
molecules on different chiralities and diameters of single carbon nanotubes is
investigated in terms of energetic, electronic properties and surface
reactivity. We found that the adsorption of CO and CO2 gas molecules
is dependent on the chiralities and diameters of CNTs and it is vice versa for
NO and NO2 gas molecules. Also, the electronic character of CNTs is
not affected by the adsorption of CO and CO2 gas molecules while it
is strongly affected by NO and NO2 gas molecules. In addition, it is
found that the dipole moments of zig-zag CNTs are always higher than the
arm-chair CNTs. Therefore, we conclude that the zig-zag carbon nanotubes are more
preferred as gas sensors than the arm-chair carbon nanotubes, especially for
detecting NO and NO2 gas molecules.