Effect of Humid Aging on the Oxygen Adsorption in SnO2 Gas Sensors
AbstractTo investigate the effect of aging at 580 °C in wet air (humid aging) on the oxygen adsorption on the surface of SnO2 particles, the electric properties and the sensor response to hydrogen in dry and humid atmospheres for SnO2 resistive-type gas sensors were evaluated. The electric resistance in dry and wet atmospheres at 350 °C was strongly increased by humid aging. From the results of oxygen partial pressure dependence of the electric resistance, the oxygen adsorption equilibrium constants (K1; for O− adsorption, K2; for O2− adsorption) were estimated on the basis of the theoretical model of oxygen adsorption. The K1 and K2 in dry and wet atmospheres at 350 °C were increased by humid aging at 580 °C, indicating an increase in the adsorption amount of both O− and O2−. These results suggest that hydroxyl poisoning on the oxygen adsorption is suppressed by humid aging. The sensor response to hydrogen in dry and wet atmosphere at 350 °C was clearly improved by humid aging. Such an improvement of the sensor response seems to be caused by increasing the oxygen adsorption amount. Thus, the humid aging offers an effective way to improve the sensor response of SnO2 resistive-type gas sensors in dry and wet atmospheres. View Full-Text
Share & Cite This Article
Suematsu, K.; Ma, N.; Watanabe, K.; Yuasa, M.; Kida, T.; Shimanoe, K. Effect of Humid Aging on the Oxygen Adsorption in SnO2 Gas Sensors. Sensors 2018, 18, 254.
Suematsu K, Ma N, Watanabe K, Yuasa M, Kida T, Shimanoe K. Effect of Humid Aging on the Oxygen Adsorption in SnO2 Gas Sensors. Sensors. 2018; 18(1):254.Chicago/Turabian Style
Suematsu, Koichi; Ma, Nan; Watanabe, Ken; Yuasa, Masayoshi; Kida, Tetsuya; Shimanoe, Kengo. 2018. "Effect of Humid Aging on the Oxygen Adsorption in SnO2 Gas Sensors." Sensors 18, no. 1: 254.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.