Mixed potential type methanol gas sensor based on Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode

With the development of methanol fuel cell vehicles, the hidden danger of methanol leakage has become a safety problem that cannot be ignored. The timely and effective detection of methanol is the premise to ensure safety. Herein, a mixed potential type methanol sensor was developed using Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode. The fabricated sensor can realize effective detection in a wide range of 0.2-1000 ppm with the sensitivities of - 4.7 mV/ppm and - 55.9 mV/decade to 0.2-5 ppm and 5-1000 ppm methanol. The sensing behavior of the sensor is explained based on mixed potential sensing mechanism in two cases of charge transfer-limiting and mass transport limiting processes. By comparing the sensing behavior under illumination conditions, it is found that the sensing performance of the mixed potential sensor can be improved by adjusting the wavelength and intensity of excitation light. The sensor possessed good repeatability, selectivity and stability in the systematic and detailed evaluation of sensing performances, which proves its potential and reliability for practical application in methanol fuel vehicles.