Surface structure of Pd-SnO2 for CO gas sensor

Abstract

SnO₂-based gas sensors are widely used for gas leakage alarm, CO detector and so on. Recently these gas sensors are being developed also under extreme situation. We reported that CO gas sensor based on SnO₂ responds reversely to small amount of CO, meaning that the electrical resistance of element increases although it usually decreases, when it is operated under lower humid condition. In this study, we aimed to investigate the conditions for which the CO gas sensor gives rise to "reverse response", and to propose the mechanism of "reverse response".