Potentiometric hydrogen sensors based on yttria-stabilized zirconia electrolyte (YSZ) and CdWO4 interface

The yttria-stabilized cubic zirconia (YSZ) based potentiometric sensor coupled with CdWO4 as the sensing electrode was developed for hydrogen detection. The developed CdWO4/YSZ/Pt sensor has found significant response to different concentration of hydrogen from 0.5 vol% to 3 vol% at 500 °C. The sensor showed good selectivity to several possible interferents such as CO, NO2 and C3H8 when the concentrations are less than 1500 ppm. The dc polarization curves and ac impedance spectra of the sensor were measured to study the sensing mechanism. The mixed-potential theory was confirmed to explain the sensing results. The reproducibility and signal repeatability of the sensor was examined to test the reliability of the sensor. The possible influence of oxygen variation and humidity in the background on the sensor response was also studied.