Synthesis, characterization and gas sensing properties of rutile TiO2 doped with Pt obtained by sol-gel method

The gas sensitive oxide TiO 2 doped with Pt was obtained by sol gel polymeric method. The reagents used as precursors were the tetra-iso- propylortotitanate alcoxide, platinum chloride, surfactant butylamonium bromide and polyvinibutyral as polymer. The molar ratio used surfactant/alcoxide=0.1. The materials were obtained as films or powders. The obtained gels were dried at 373 K and heat treated in air between 473-873 K The films were obtained by dipping method and the support was CeO 2 -Ta 2 O 5 disc. The obtained materials was characterized by XRD, SEM, TEM electron microscopy and N 2 adsorption-desorption. The sensing properties of TiO 2 Pt films were tested in NOx and CO 2 . For the 10 mg/m NO x and 5000 ppm CO 2 after 5 minutes gas exposure, the sensor voltages were 35 mV for NO x and 65 mV for CO 2 .