Theoretical study on quantum transport of carbon nanotubes for detecting toxic molecules: The role of dopants

Abstract

We study the effects of dopant atoms on quantum transport and adsorption properties of environmentally harmful (CO2), toxic (CO) and common (O2 and N2) molecules of carbon nanotubes (CNTs) based on the first-principles electronic structure and quantum transport study. It is found that CO and O2 molecules can bind on the boron (B)-doped (14,0) CNTs with relatively large adsorption energies and short binding distances in air. We also studied the quantum transport of B-doped (14,0) CNTs for the adsorption of the molecules. The quantum transport properties of the CNTs are found to be sizably varied by the introduction of a dopant atom and the adsorption of the molecules. The nature of the variation of the quantum conductance induced by the doping as well as the molecular adsorption is discussed, and the possibility to individually detect toxic CO and common O2 molecules under low bias voltages is also discussed.