A limiting current oxygen sensor with 8YSZ solid electrolyte and (8YSZ)0.9(CeO2)0.1 dense diffusion barrier

Abstract

A series of (8YSZ)1-x(CeO2)x (0 ≤ x ≤ 0.3) materials are synthesized by co-precipitation. Both crystalline structure and electrical conductivity of material are detected. (8YSZ)1-x(CeO2)x (0 ≤ x ≤ 0.3) belongs to cubic phase and (8YSZ)0.9(CeO2)0.1 is provided with the highest electrical conductivity. Select 8YSZ as solid electrolyte and (8YSZ)0.9(CeO2)0.1 as dense diffusion barrier to prepare an oxygen sensor by Pt paste bonding method. Limiting current plateau of the sensor is observable at 2% oxygen concentration and at 720–900 °C, and logarithm of the limiting current (log IL) plays a linear relationship to 1000/T. Limiting current of the sensor is observable at 850 °C and 2–14% oxygen concentration, which is linearly related to the oxygen concentration. The limiting current of the sensor does not vary significantly in the range of water vapor pressure (p(H2O)) 280.66–2268.63 Pa and in the range of carbon dioxide concentration 0–90%, respectively. The limiting current of the sensor does not decay in the oxygen concentration of 2% at 850 °C during the detection time of 120 h.