The effect of La2CuO4 sensing electrode thickness on a potentiometric NOx sensor response

In order to further understand the different contributions to NOx sensing mechanism as well as the importance of electrode geometry, solid state potentiometric sensors with varying La2CuO4 sensing electrode thicknesses were studied. These sensors (with a Pt counter electrode) showed a dependence of NO2 sensitivity which decreased with increasing thickness in the temperature range of 550–650 °C. They also showed NO sensitivity that was independent of thickness at 400 °C and 600 °C, but varied at temperatures between. This behavior was attributed to multiple mechanistic contributions explained by Differential Electrode Equilibria.