NASICON-based H2 Sensor Using CoCrMnO4 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 spinel-type 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 ℃. 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.