Solid Electrolyte CO2 Sensor Using Binary Carbonate Electrode

Abstract A simple potentiometric CO2 sensor based upon a Na+-conducting solid electrolyte (NASICON) was found to be greatly improved in response time and water vapor-resistance by using a binary carbonate electrode of BaCO3–Na2CO3. For a wide range of CO2 concentration from 4 to 400000 ppm, the electromotive force examined at 823 K followed a Nernst’s equation excellently, with a 90% response time of as short as 8 s. Water vapor hardly affected the sensor characteristics, in contrast to the case of a pure Na2CO3 electrode.