Garnet-like solid state electrolyte Li6BaLa2Ta2O12 based potentiometric CO2 gas sensor

A new electrochemical cell for CO2 sensing has been set up using garnet-like solid electrolyte Li6BaLa2Ta2O12 and Li0.36WO3 as a reference electrode. The electromotive force (EMF) of the cell, the reproducibility and the long-term stability of the sensor signals have been examined at temperature between 300 and 500 degrees C. The EMF was found to be dependent on the partial pressure of CO2 (pCO(2)) and could be expressed by the Nernst equation. The sensitivity of the sensors was 73 mV/decade and 75 mV/decade at 450 and 500 degrees C, respectively. It was also seen that the sensor showed fast response for CO2 and the sensor signals was found to be highly reproducible and stable for several days. (C) 2012 Elsevier B.V. All rights reserved.