Comparison of Pt and Pd Modified TiO sub(2) Gas Sensors

Pt and Pd have been widely used to improve response properties of TiO sub(2) based gas sensors. In this work, differences on response properties, especially the response time of Pt/TiO sub(2) and Pd/TiO sub(2) sensors, were carefully compared. TiO sub(2) sensing films were modified by dipping method using H sub(2)PtCl sub(6) and PdCl sub(2), respectively. XRD, XPS and SEM were used to characterize the crystal structure, elemental composition and grain size of the sensing films. The defect state was characterized by the relationship between resistance and oxygen partial pressure. And the response transients to H sub(2) and O sub(2) were tested by voltammetry method. The difference on response properties of modified TiO sub(2) sensors were suggested to arise from activation energy.Original Abstract: Pt ir Pd placiai naudojami siekiant pagerinti TiO sub(2) duju jutikliu savybes. Siame darbe lyginta Pt/TiO sub(2) ir Pd/TiO sub(2) jutikliu reakcijos sparta. Jutikliui naudotos TiO sub(2) pleveles buvo modifikuojamos panardinant atitinkamai i H sub(2)PtC sub(16) ir PdCl sub(2) tirpalus. Jutikliu pleveles kristalines strukturos, elementines sudeties bei grudetumui ivertinti buvo naudojami XRD, XPS bei SEM. Defektu bukle buvo ivertinta matuojant pleveliu varza skirtinguose daliniuose deguonies slegiuose. Voltamperometrijos metodu buvo istirta jutikliu atsako kinetika H sub(2) ir O sub(2) poveikiui. Paaiskinta, kad modifikuotu TiO sub(2) jutikliu atsako skirtumai atsiranda del skirtingu aktyvacijos energiju.