H2 Sensor Based on Au/TiO2 Nanoparticles by Flame-Made

TiO2 is used extensively as a gas sensing material due to its change in electrical conductivity under analyst gas exposure. Gold (Au) is a good catalyst that promotes chemical reactions by reducing the activation energy between sensing film and particular gas. Pure TiO2 and TiO2 nanoparticles doped with 0.25-0.75 at% Au were successfully produced in a single step by Flame spray pyrolysis (FSP) technique. The structure and morphology of as-prepared products have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). TiO2 and Au-doped TiO2 nanoparticle films were prepared by spin-coating technique. The gas sensing of H2 was studied at the operating temperatures ranging from 300-350°C in dry air. It was found that the TiO2 doped with Au sensing film showed higher response of H2, with faster response time (within second) than pure TiO2 sensing film. The response increased and the response time decreased with increasing H2 concentrations