CARBON-DIOXIDE SENSOR USING NASICON PREPARED BY THE SOL-GEL METHOD

Solid-electrolyte sensors using NASICON for detecting CO2 gas are prepared by the sol-gel method. Starting materials are the alkoxides Si(OC2H5)(4), Zr(OC2H9)(4), PO(OC4H9)(3) and NaOC2H5. Because of their fine powders, the sintering temperature can be low. The phase identification is carried out by X-ray diffractometry (XRD). E.m.f. cells are constructed by fixing the NASICON disk to the end of a quartz tube with an inorganic adhesive. The devices with (Li, Ba)CO3 as sensing electrode and air as reference electrode show high sensitivity to 300-5000 ppm CO2 gas and good stability for a sintering temperature of 1000 degrees C.