Enhanced Gas Sensing Performances of ZnO-based Composite Nanostructures

Currently, new nanostructured materials based on composite metal oxides are of great interest for the development of gas sensors with improved functional characteristics. In this work, zinc oxide nanowires were synthesized by hydrothermal method. Hierarchical ZnO/ZnFe2O4 nanostructures were obtained by immersion of zinc oxide layers in ferrous sulphate aqueous solutions of different concentrations. Zn-Sn-O nanostructures were synthesized by hydrothermal processing of ZnO nanowires in an aqueous-alcohol solution of potassium stannate and urea. The mechanism of composite nanostructures is considered. It was found that the sensitivity of composite structures to isopropyl alcohol vapors significantly exceeds the one of initial zinc oxide nanowires. The improvement of gas-sensitive properties is associated with the presence of various types of surface centers that participate in the adsorption and oxidation of isopropyl alcohol.