Dispersion-corrected DFT study on the carbon monoxide sensing by B2C nanotubes: effects of dopant and interferences

Electrical sensitivity of a boron carbon nanotube (B2CNT) was examined toward carbon monoxide (CO) molecule by using dispersion-corrected density functional theory calculations. It was found that CO is weakly adsorbed on the tube, releasing energy of 3.5-4.1 kcal/mol, and electronic properties of the tube are not significantly changed. To overcome this problem, boron and carbon atoms of the tube were substituted by aluminum and silicon atoms, respectively. Although both Al and Si doping make the tube more reactive and sensitive to CO, Si doping seems to be a better strategy to manufacture CO chemical sensors due to the higher sensitivity without deformation of nanotube structure after adsorption procedure. Moreover, it was shown that some interference molecules such as H2O, H2S and NH3 cannot significantly change the electronic properties of B2CNT. Therefore, the Si-doped tube might convert the presence of CO molecules to electrical signal.