Skip to Main Content
A low-temperature lithium ion based potentiometric CO2 sensor has been developed by adding 10 mol% of SiO2, B2O3, Li2O, and Bi2O3 composite metal oxide mixture to (Li2-Ba)CO3 sensing bicarbonate. The sensors added with different mol% of oxides were tested at different operating temperatures. The sensor with 1:2:1:1 mol% of the SiO2:B2O3:Li2O:Bi2O3 composite metal oxide showed a fair Nernstian correlation and obtained n value equal to 2 at 300degC, where n is the number of reaction electrons. A glassy sensing phase resulted that improved response and recovery. The sensor is also found stable against humidity (70% RH) at 300 degC. However, it is further observed that the performance of the sensor deteriorated with increasing Li2O or decreasing B2O3 content. The sensor performance could further be improved at lower temperatures with the introduction of dioctyl phthalate (DOP) plasticizer into the sensing electrode.