A DFT study for adsorption of CO and H2 on Pt-doped ZnO nanocluster

Abstract

Using density functional theory calculations, we studied structural, electronic and adsorption properties of CO and H2 adsorption on the Pt-doped (ZnO)12 nanoclusters. The more suitable position for the Pt atom is its lateral doping on the nanocluster surface. The lower energy gap for the Pt-doped (ZnO)12 nanoclusters denotes that their conductivity is higher in comparison with the bare nanocluster. The results showed quite a reasonable increase in CO and H2 gas molecules adsorption energies on the nanoclusters compared with the pristine (ZnO)12 due to Pt doping. The sensitivity of the electronic and adsorption properties to the number of molecules was calculated as well. Upon CO adsorption on the Pt-doped (ZnO)12 nanoclusters energy, it is better when no more than two molecules can be attached to one Pt atom, while H2 adsorption provides at least three hydrogen molecules on Pt atom. Also, changes in electronic spectra of nanoclusters under the influence of adsorbed CO and H2 molecules imply a decline in conductivity in such systems. These investigations proved that the Pt-doped (ZnO)12 nanoclusters can be proposed as an approachable candidate in gas sensors for detecting CO and H2 gas. Also, the calculation results of H2 adsorption on Pt-doped (ZnO)12 nanoclusters can help in consideration of the possibility of hydrogen storage media creation.