Potentiometric gas sensors based on fast solid electrolytes

Abstract

The application of small all-solid-state galvanic cells for monitoring NO 2, CO 2 and O 2 partial pressures at ambient or slightly increased temperatures is demonstrated. The approach makes use of a gas-sensitive mixed conducting thin layer, which rapidly relates the activity of the gaseous species to the activity of the mobile component according to the Gibbs-Duhem relationship. A reversible change of the potential as a function of the partial gas pressure is observed for the different galvanic cells, which are preferably based on Na +-β/β″-alumina and α-AgI solid electrolytes.