Assessment of DFT Calculations and Molecular Dynamics Simulation on the Application of Zinc Oxide Nanotube as Hydrogen Cyanide Gas Sensor

In this study, to providing the valuable insights into the develop a novel gas sensor for the detection of hydrogen cyanide (HCN), we have employed the molecular dynamics simulation in order to examine the adsorption of carbon monoxide (CO), nitrous oxide (N2O), nitrogen (N2) and HCN gas molecules on the surface of zinc oxide nanotube (ZnONT). More tendencies of the HCN molecules for the adsorption on the nanotube surface contrary to the other considered gases in the simulation study indicate that ZnONT can be a suitable sensor for the HCN gas molecule. Moreover, the detailed studies about the effect of the HCN adsorption on the electronic properties of ZnONT are performed by the density functional theory (DFT) calculation. The negative values of the adsorption energies (Eads) and the small transferred charge from ZnONT to the gas molecule indicate that the adsorption of the HCN gas on the surface of the nanotube is weak. The atom in molecules (AIM) analysis reveals the partially covalent nature of the intermolecular interaction between HCN gas molecule and the nanotube.