Relationships between sensitivity, catalytic activity, and surface areas of SnO 2 gas sensors

Abstract

SnO 2 having different surface areas were synthesized using a surfactant-templating synthetic method. The effects of surface areas of the obtained SnO 2 on their gas sensing and catalytic properties were investigated. Interestingly, a linear relationship was found between the surface areas of SnO 2 and their gas sensitivities to H 2 and CO. Furthermore, a linear relationship was observed between the surface areas and the catalytic activities of SnO 2 in the oxidation of H 2 and CO. Based on the fact that the mechanisms for catalytic reactions and gas-sensing processes both involve surface adsorption and reaction between surface-adsorbed oxygen species and surrounding gases (H 2 or CO), the relationship between these two mechanisms occurring on SnO 2 surfaces is discussed.