Synthesis of ZnO Nanorod/TiO2 Nanotube and its Application as a Resistive Gas Sensor

In this study, different chemical methods were used to synthesize ZnO nanorod, TiO₂ nanotube and ZnO/TiO₂ nanostructure as high sensitivity vapor sensor for ethanol. The surface topography of ZnO nanorod, TiO₂ nanotube and ZnO/TiO₂ was studied by using the scanning electron microscopy (SEM). The X-rays diffraction showed the appearance of (101) ZnO which has single crystalline with a hexagonal wurtzite while TiO₂ has been crystallized in a tetragonal with the preferential orientation of the crystallinity with the prominent (111). The relation between resistance-time showed high sensitivity for ZnO/TiO₂ and was found to be around 20-80% at different working temperature. ZnO/TiO₂ sensor was the most sensitive to ethanol vapor.