Properties of Nasicon-based CO2 sensors with Bi8Nb2O17 reference electrode

Potentiometric CO2 sensors based on Nasicon (Na+ conductor, Na3Zr2Si2PO12) electrolyte, Bi8Nb2O17/Pt reference electrode and different sensing electrodes have been prepared. Besides the sensing electrode material, sensors differ from each other in the reference electrode preparation technique. The main aim of this study is to investigate sensor construction and electrode fabrication process influence on sensor properties. The optimal operating temperature of the studied sensors was 500 °C. At this temperature the electromotive force (EMF) responses of all sensors were linearly dependent on logarithm of CO2 partial pressure. It was found that the presence of Bi8Nb2O17 reference layer reduces interference of oxygen partial pressure on sensor response.