Theoretical study of aluminum nitride nanotubes for chemical sensing of formaldehyde

Semiconductive carbon nanotubes (CNTs) have demonstrated great sensitivity toward molecules such as NH3, NO, and NO2. Nevertheless, pristine CNTs cannot be used for detection of some highly toxic molecules such as formaldehyde (HCOH). In the present study, we examined the possibility of using aluminum nitride nanotubes (AlNNTs) as a potential gas sensor for HCOH detection by performing density functional theory (DFT) calculation. It was found that HCOH molecule can be chemisorbed on the surface of AlNNTs with Gibbs free energies of −0.59 to −0.64 eV, at standard temperature and pressure (STP, 1 atm and 298 K). In view of the high change of HOMO/LUMO energy gap of the tube during the chemisorption, it is expected that the process induce a significant change in its electrical conductivity. Hence, the AlNNT can be used as a potential efficient gas sensor for HCOH detection. Furthermore, it was shown that H2O molecules cannot significantly change the electronic properties of AlNNTs.