Density functional study of Al/N co-doped (10,0) zigzag single-walled carbon nanotubes as CO sensor

Al/N co-doped (10,0) SWCNT was investigated through density functional theory (DFT) calculations to find out its sensing properties for the toxic CO gas. The results were compared with pristine, aluminum and nitrogen doped (10,0) SWCNT. The CO molecule was adsorbed to different sites of the modified nanotubes and their geometric structures and electronic properties before and after CO adsorption were investigated. The results show that the adsorption of CO molecule, does not change the properties of pristine (10,0) SWCNT, and has little effect on band structure and DOS of N or Al doped SWCNT. However, adsorbing the CO molecule to Al/N co-doped SWCNT reduces the band gap and changes its electronic properties considerably. So Al/N SWCNT is potentially a good CO sensor. (C) 2013 Elsevier B.V. All rights reserved.