CO gas sensing properties of Pd- and Al-doped zinc oxide nanotubes: a DFT study

Abstract

Surface engineering and doping of zinc oxide (ZnO) nanostructures have been two feasible techniques for improving the gas-detecting capability of these nanostructures. However, the role of fundamental processes and factors that affect this improvement has not been fully understood. In this study, the adsorption of CO gas molecules on Pd- and Al-doped ZnO nanotubes is investigated using the first-principles calculations. The binding strength and charge transport as well as some other structural and electronic properties of these nanotubes are studied. The calculation results indicate the active interaction of CO gas molecules with Pd- and Al-doped ZnO nanotubes at high adsorption energies. The results provide a better atomistic insight and a more comprehensive explanation of the improvements in the electrical properties and sensing capabilities of Pd- and Al-doped ZnO.