Comparison of Pt and Pd Modified TiO2 Gas Sensors

Pt and Pd have been widely used to improve response properties of TiO2 based gas sensors. In this work, differences on response properties, especially the response time of Pt/TiO2 and Pd/TiO2 sensors, were carefully compared. TiO2 sensing films were modified by dipping method using H2PtCl6 and PdCl2, 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 H2 and O2 were tested by voltammetry method. The difference on response properties of modified TiO2 sensors were suggested to arise from their activation energy. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6403