Sensing behavior of solid-state impedancemetric NOx sensor using solid electrolyte transducer and oxide receptor

Solid-electrolyte impedancemetric NOx (NOx; NO, NO2) sensor devices were designed by using metal oxides (Fe2O3, Co3O4, NiO, CuO, ZnO) as a receptor material and an 8 mol%-yttria-stabilized zirconia (YSZ) plate as a solid electrolyte transducer material. The sensing signal could be simply detected as the impedance change of the transducer. The sensing performance of the impedancemetric NOx sensor for the detection of NOx in the range 10-150 ppm at 300-500 °C was investigated using impedance analyzer. Among the sensor device tested NiO/YSZ sensor showed good sensing properties for NO and NO2 at 400 °C on 100 kHz. Moreover, the sensing response properties showed good selectivity and stability to NO2.