A theoretical study of silicon-doped boron nitride nanotubes serving as a potentialchemical sensor for hydrogen cyanide

Abstract

In order to search for a novel sensor to detect and control exposure to hydrogen cyanide(HCN) pollutant molecule in environments, the reactivities of pristine and silicon-doped(Si-doped) (8, 0) single-walled boron nitride nanotubes (BNNTs) towards the HCNmolecule are investigated by performing density functional theory (DFT) calculations. TheHCN molecule presents strong chemisorption on both the silicon-substituted boron defectsite and the silicon-substituted nitrogen defect site of the BNNT, which is insharp contrast to its weak physisorption on pristine BNNT. A remarkable chargetransfer occurs between the HCN molecule and the Si-doped BNNT as proved bythe electronic charge densities. The calculated data for the electronic densityof states (DOSs) further indicate that the doping of the Si atom improves theelectronic transport property of the BNNT, and increases its adsorption sensitivitytowards the HCN molecule. Based on calculated results, the Si-doped BNNTis expected to be a potential resource for detecting the presence of toxic HCN.