Cyanogen, Methylacetylene, Hydroquinone, Ethylacetylene, Aniline, Pyrrole, and Ethanol Detection by Using BNNT: DFT Studies

Electrical sensitivity of a Boron Nitride Nano Tube (BNNT) was examined toward hydroquinone (C6H4(OH)2), cyanogens (C2N2), methylacetylene (C3H4), ethylacetylene (C4H6), aniline (C6H5NH2), ethanol (C2H5OH), pyrrole (C4H5N), molecules by using Density Functional Theory (DFT) calculations at the B3LYP/6-31G(d) level of theory. In considering the dsorption energy (Ead) of those molecules on the BNNT are sequenced: C6H5NH2(Ead= -47.55kcal/mol)> C4H5N (Ead=-26.66kcal/mol) >C2H5OH(Ead= -25.91kcal/mol)> (CN)2(Ead=-20.70kcal/mol)> C6H4(OH)2(Ead= -20.21kcal/mol) >C3H4(Ead=-12.73kcal/mol)> C4H6(Ead=-11.19kcal/mol). According to this comparison aniline molecule with Ead=-47.55 kcal/mol has the most adsorption energy among all molecules. Calculations showed that when the nanotube was doped by Si and Al atoms, the amount of HOMO/LUMO energy gap (Eg) reduced significantly. This reduced showed that BNNT is a suitable semiconductor after doping and the doped BNNT in the presence of those gases generates an electrical signal and therefore can be used potentially for gas sensors. Recent researches demonstrate that Boron nitride nanotube is a suitable adsorbent for detection and separation of those compounds.