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

Using density functional calculations, we have investigated the adsorption of a H 2 S molecule on the pristine and Si-doped BeO nanotubes (BeONT). It was found that the H 2 S 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 H 2 S molecule. Therefore, the process of Si doping provides a good strategy for improving the sensitivity of BeONT to toxic H 2 S, which cannot be trapped and detected by the pristine BeONT. Also, the emitted electron current density from the Si O –BeONT will be significantly increased after the H 2 S adsorption.