NASICON-based potentiometric Cl_2 sensor combining NASICON with Cr_2O_3sensing electrode

摘要

This work focuses on the sensing performance of the sensor to chlorine (Cb) gas in air based on sodium super ionic conductor (NASICON) and oxide electrode. Among eight single oxides examined, Cr_2O_3 exhibited the highest sensitivity to Cl_2 gas in air at 300 ℃. △EMF values of the sensing device attached with Cr_2O_3 changed linearly with the logarithm of Cb concentration in the range of 5-50 ppm. The sensitivity of the sensors was testified by using Cr_2O_3 electrode sintered with different temperature. The sensor using Cr_2O_3 sintered at 600 C showed the largest sensitivity to Cl_2 at 300 ℃. Through burying the reference electrode in middle of the NASICON layer and decreasing the area of the reference electrode, the sensitivity of the sensor to Cb can be greatly improved. Finally, a sensing mechanism related to the mixed potential was proposed for the sensor based on NASICON and oxide electrode.