Ruize Sun

Sub-ppm H2S sensor based on NASICON and CoCr2−xMnxO4 sensing electrode

Solid electrochemical sensors based on sodium super ionic conductor (NASICON) and spinel-type oxide CoCr2−x MnxO4 (x = 0, 1, 1.2, 1.4 and 2) sensing electrode were designed for sub-ppm H2S detection. In comparison with other spinel-type oxides, the sensor using CoCr1.2Mn0.8O4 showed the maximum response of 178 mV for 10 ppm H2S at 250 °C. The sensor displayed good stability for H2S during the testing period. Moreover, the sensor exhibited excellent selectivity toward H2S against the other interference gases, such as SO2, NO2, CH4, CO, C2H4, H2 and NH3. A sensing mechanism related to the mixed potential was proposed for the sensor based on NASICON and oxide electrodes. The effect of sintering temperature had also been investigated.

NASICON-based H 2 sensor using CoCrMnO 4 insensitive reference electrode and buried au sensing electrode

This work focuses on the H2 sensing performance of the sensor with buried Au sensing electrode and spineltype oxide CoCrMnO4 insensitive reference electrode within sodium super ionic conductor(NASICON) film. The sensor showed the highest response to H2 gas on the insensitive material sintering at 800 °C. Compared with those of the traditional structure device, the sensitivity and selectivity of the sensor using buried sensing electrode were greatly improved, giving a response of −177 mV in 9×10−5 g/L H2, which was about 3.5 times higher than that of sensors with traditional structure. Moreover, the ΔV value of the sensing device exhibited linear relationship to the logarithm of H2 concentration and the sensitivity(slope) was −135 mV/decade. A sensing mechanism related to the mixed potential was proposed for the present sensor.