Density functional study on the sensing properties of nano-sized BeO tube toward H2S

Abstract

Using density functional calculations, we have investigated the adsorption of a H2S molecule on the pristine and Si-doped BeO nanotubes (BeONT). It was found that the H2S molecule is physically adsorbed on the pristine BeONT with adsorption energies ranging from 3.0 to 4.2 kcal/mol. Substituting a Be or O atom of the tube by Si increases the adsorption energy to 6.9–17.2 kcal/mol. We found that substituting an O atom by Si makes the electronic properties of the BeONT strongly sensitive to the H2S molecule. Therefore, the process of Si doping provides a good strategy for improving the sensitivity of BeONT to toxic H2S, which cannot be trapped and detected by the pristine BeONT. Also, the emitted electron current density from the SiO–BeONT will be significantly increased after the H2S adsorption.