Mixed-potential NH3 sensor based on Ce0.8Gd0.2O1.9 solid electrolyte

Gadolinia-doped ceria (GDC) prepared by the oxalate coprecipitation method was used as an oxygen-ion conducting solid electrolyte for a mixed-potential ammonia gas sensor with a WO3-sensitive electrode. The sensing performance of this sensor was compared with a sensor based on yttria-stabilized zirconia (YSZ) electrolyte. The influence of different oxygen-ion electrolytes on the performance of the gas sensor was evaluated. The test results show that the sensor device is much more sensitive (140.44 mV/decade) than the YSZ-based sensor device. Furthermore, the also shows good repeatability and stability. The electrochemical impedance measurements indicate that the GDC-based sensor's high performance may benefit from the high conductivity of GDC.