Nasicon-based potentiometric Cl2 sensor using Cr2O3 sensing electrode

A NASICON-based electrochemical device attached with an oxide electrode was developed for the detection of Cl
₂
in air at high temperature. Among the oxides tested, Cr
₂
O
₃
was found to be the best suited for the sensing electrode. The ΔEMF value of the device attached with Cr
₂
O
₃
was almost linear with the logarithm of 5-50 ppm Cl
₂
concentration. It was also observed that the sensor showed a speedy response and recovery kinetics to Cl
₂
. In addition, the device exhibited excellent selectivity to Cl
₂
against the other interference gases, such as CO, NO, NO
₂
, H
₂
, C
₇
H
₈
, C
₂
H
₄
and CH
₄
. The buried reference electrode can effectively improve the sensitivity of the sensor.