NO2 adsorption behaviour on LaFeO3 electrodes of YSZ-based non-nernstian electrochemical sensors

X-ray photoelectron spectroscopy (XPS) was used to examine the NO2 adsorption behaviour on the LaFeO3 and Pt electrodes of planar yttria stabilized zirconia non-Nernstian gas sensors. The electrochemical sensors were exposed to the same gas atmosphere containing 1000 ppm NO2 at 650°C. XPS of the as-prepared sensors and sensors after exposure to NO2 revealed bonded nitrogen peaks on the surface of the semiconducting oxide but no nitrogen peaks on the Pt electrode. Therefore, NO2 adsorption on a LaFeO3 electrode plays an important role in the NO2 detection mechanism.