The gas sensing properties of boron nitride nanotubes (BNNT) and C-doped BNNT for some small gas molecules, such as CH4, CO2, H2, H2O, N2, NH3, NO2, O2, F2, and so on, have been investigated by using the density functional theory calculations, showing that BNNT can present a low sensitivity to the gaseous CH4, CO2, H2, H2O, N2 and NH3 molecules and a high sensitivity to the gaseous O2, NO2 and F2 molecules. The electronic structures of BNNT and C-doped BNNT present dramatic changes after the adsorption of O2, NO2 and F2 molecules. Although C-doped BNNT can improve the interaction between the gas molecules and the BNNT, the sensitivity of C-doped BNNT can not be changed, compared with that of the pristine BNNT. So BNNT and C-doped BNNT would be promising candidates for serving as effective sensors to detect the presence of O2, NO2 and F2 molecules.

Key words: boron nitride nanotube, gas molecule, C-doped, gas sensor, density functional theory