Abstract
Aimed at automobile exhaust monitoring of NOx, a new-type amperometric sensor was fabricated by using yttria-stabilized zirconia (YSZ) as electrolyte and a nano-structured perovskite-type oxide Gd0.2Sr0.8FeO3−δ (GSF) as sensing-electrode (SE) prepared by impregnating method. The fabricated sensor was examined for detection of NO2 at high operating temperatures (500–800 °C) in N2 carrier gas. It was found that the response current of the sensor was almost linear to NO2 concentration from 25 to 500 ppm at 500–800 °C when SE was polarized at −400 mV. The sensitivity of the sensor reached 2.61 μA ppm−1 at 800 °C. The sensor showed good selectivity, response, reproducibility and stability to NO2.