A limiting current oxygen sensor with (CuO)0.1(8YSZ)0.9 dense diffusion barrier

In this paper, (CuO)(x)(8YSZ)(1-x) (0 <= x <= 0.3) is prepared by using a co-precipitation method. Its electrical conductivity increases to a maximum at (CuO)(0.1)(8YSZ)(0.9), and then decreases with increasing CuO doping content. An oxygen sensor is fabricated by Pt paste method based on 8YSZ (8 mol% Y2O3 stabilized ZrO2) solid electrolyte and (CuO)(0.1)(8YSZ)(0.9) dense diffusion barrier for the first time. A limiting current of the sensor is reached under different conditions, such as temperature (T) of 720-870 degrees C, oxygen concentration (x(O-2)) of 0-4%, carbon dioxide concentration (x(CO2)) of 0-100%, water vapor pressure (p(H2O)) of 280.66-2268.63 Pa, and testing time of 120 h. The oxygen sensor exhibits excellent sensing performances, its single selectivity to oxygen and resistance to interference from other gases. Moreover, the performances of the oxygen sensor do not decay and remain well under long-term high temperature operation.