Synthesis of Sn doped ZnO/TiO2 nanocomposite film and their application to H2 gas sensing properties

Tin doped Zinc oxide/Titanium oxide nanocomposite (TZO/TiO2) was prepared by two methods: TiO2 nanotube (Nt) arrays are grown by anodic oxidation of titanium foil and TZO films was deposited on the TiO2 Nt obtained by hydrothermal process. The morphological characteristics and structures of ZnO/TiO2 and TZO/TiO2 were examined by (scanning elecron miscroscopy) SEM, (X rays diffraction) XRD and (energy dispersive spectroscopy) EDS analysis. The diameter of TiO2 Nts was ranged from 40 nm to 90 nm with wall thicknesses of approximately 10 nm. The anatase structure of Titania, the hexagonal Zincite crystal of zinc oxide and tetragonal structure of tin oxide were identified by XRD. EDS analysis revealed the presence of O, Zn, Ti and Sn elements in the obtained deposits.These nanocomposites have been used as active layer in hydrogen gas sensing application. The hydrogen sensing characteristics of the sensor was analyzed by measuring the sensor responses in the temperature of 100 °C and 160 °C. The highest gas response is approximately 1.48 at 160 °C.The sensing mechanism of the nanocomposite sensor was explained in terms of H2 chimisorption on the highly active nanotube surface.