Gas-sensitive composite nanostructures based on zinc oxide for detecting organic solvent vapors

Abstract

The paper shows the possibilities of using ZnO-Fe composite structures as gas-sensitive layers for detecting organic solvent vapors exemplifying on isopropyl alcohol. Composite structures were formed based on zinc oxide nanorods synthesized by the hydrothermal method, due to changes in their composition in a ferrous sulfate solution. The chemical composition of the surface was studied using X-ray photoelectron spectroscopy. It is shown that when using a ferrous sulfate solution with a concentration of 0,025 mol/l, iron and zinc atoms are observed on the surface. An increase in the concentration of the solution to 0,05 mol/l leads to the deposition of iron oxide particles on the surface of the nanorods. The study of some gas-sensitive characteristics was carried out at 250°C when exposed to isopropyl alcohol vapors in the concentration range from 200 to 1000 ppm. It was found that the response value of composite structures ZnO-Fe (0,025) exceeds the corresponding value for the zinc oxide nanorods, that may be due to the high content of oxygen vacancies in the composite sample.

Keywords

• zinc oxide
• gas sensors
• composite nanostructures
• x-ray photoelectron spectroscopy
• organic solvent