La2CuO4 sensing electrode configuration influence on sensitivity and selectivity for a multifunctional potentiometric gas sensor.

The effects of electrical contact configuration for La2CuO4 sensing electrodes for a planar-based potentiometric gas sensor were studied in order to further quantify the effects of processing on sensor performance. Five configurations of La2CuO4 were used for the sensing electrode. The La2CuO4 sensing electrode was screen printed opposite a Pt counter electrode on a tape cast YSZ electrolyte. Three sensors were prepared for each configuration to test repeatability. Each sensor was tested at temperatures from 400 to 700 ◦C at various concentrations of NO2, NO, and CO in an environment of 3% O2 with a balance of N2. Results show that these sensors exhibit suitable sensitivity to all the gases tested. More importantly, it was shown that the sensitivity, selectivity/cross-sensitivity, and repeatability of these sensors are dependent on the sensing electrode configuration.