Highly Selective Mixed Potential Methanol Gas Sensor Based on a Ce_0.8Gd_0.2O_1.95 Solid Electrolyte and Au Sensing Electrode

Abstract

A Ce 0.8 Gd 0.2 O 1.95 -based mixed potential type sensor attached with a commercially available Au paste sensing electrode material was fabricated to detect methanol. The optimum working temperature of the sensor was 545 °C, and the response value to 100 ppm methanol was −53 mV. The selectivity of the sensor was poor. The addition of a 4A molecular sieve filter layer and the method of pattern recognition were combined to improve it. Only gas molecules smaller than the pore diameter of the 4A molecular sieve were able to pass through the zeolite channel, and the selectivity coefficient of the sensor to methanol was improved by adding the filter layer. Meanwhile, there was an obvious distinction between the response and recovery times of the sensor toward methanol, ethanol, acetone, n-butanol, and n-pentanol. Next, the pattern recognition method was adopted. The relationship between the response value and the logarithm of gas concentration and the relationship between the maximum rate of the response process and the gas concentration were plotted separately. By comprehensively considering the two characteristic parameters of the response value and the maximum value of the differential response signal, the purpose of qualitative identification of gas types and quantitative analysis of gas concentrations was hopefully achieved.

Mixed Potential Type Isoprene Sensor for the Application in Real-Time Monitoring of Biomarker Gases

“…However, the load of Au increases the basic resistance of the sensor nearly 10 times to the level of GΩ, which is detrimental to signal detection. In contrast, sensors based on the mixed potential sensing mechanism present incomparable advantages in stability and humidity resistance, which have been confirmed in the highly stable detection of NO x , − SO 2 , , NH 3 , and volatile organic compounds (VOCs) − gases. Unfortunately, there are still very limited reports on mixed potential gas sensors for isoprene detection.…”

Pattern Recognition with Temperature Regulation: A Single YSZ-Based Mixed Potential Sensor Classifies Multiple Mixtures of Isoprene, n-Propanol, and Acetone

“…Compared with other gas detection instruments, − mixed potential-type sensors possess the advantages of low cost, simple structure, rapid response and recovery speed, and miniaturization. − YSZ-based mixed potential gas sensors have been demonstrated to be a powerful tool for VOC detection due to their superior sensitivity, high temperature resistance, and good mechanical and chemical stability. − However, the relatively poor selectivity of such a single sensor has always been the main roadblock hindering its wide application. Therefore, distinguishing various gas compositions through a single sensor is a big challenge in the mixed potential gas sensor field.…”