CeO2-based mixed potential type acetone sensor using La1-xSrxCoO3 sensing electrode

In this article, CeO2-based mixed potential type gas sensor attached with sensing electrodes (SEs) consisting of perovskite-type La1-xSrxCoO3 (x = 0.1, 0.2, 0.3 and 0.5) composite oxides has been developed for acetone detection. The effect of different Sr2+ doping content in La1-xSrxCoO3 oxide material and calcination temperature on acetone sensing characteristics was investigated. It was seen that the sensor using La0.8Sr0.2CoO3 calcined at 1000 °C as SE gave the largest sensing signal to acetone in the concentration range of 1-50 ppm at 600 °C among these sensors. The response value (ΔV) of the sensor was sectionally linearly changed with the logarithm of acetone concentration within the ranges of 1-5 ppm and 5-50 ppm, and the sensitivities were −26 and −49 mV/decade, respectively. In addition, it is noteworthy that the response of the sensor to 1 ppm acetone was approximately −8.7 mV. The sensor also exhibited consistent response and recovery characteristics in five cycles, indicating the sensing device had good reproducibility. Besides, the sensor exhibited the highest response to 10 and 50 ppm acetone and less effective response to other tested gases, it indicates that the sensor has good selectivity. Furthermore, the long-term stability for the sensor to 20 ppm acetone was good because that only a slight attenuation in the sensing response was observed during 30 days. The sensing characteristics of the sensor attached with La0.8Sr0.2CoO3-SE sintered at 1000 °C to acetone were explained in terms of electrocatalytic activity changes induced by effects of doped Sr divalent cation.