Potentiometric NO2 Sensor Based on YSZ and WS2

In this study, Yttria-stabilized zirconia (YSZ) electrochemical sensors attached with the WS2 sensing electrode (SE) were fabricated and examined for NO2 sensing properties. Due to its internal stratiform structure, surface and edge of the lamella have high chemical activity, WS2 was used as a kind of highly efficient catalyst. WS2 was partial oxidated to WO3 at 400°C, and with the increment of temperature, oxidation will accelerate. The ΔEMF to 500 ppm NO2 was as high as 125mv at 400°C, while the value of WO3-based sensor was as small as 10 mv in the same condition. These WS2-attached devices gave a linear correlation between EMF and the logarithm of NO2 concentration from 30 to 500 ppm in the temperature range 350–500°C. The response time of the device is about 1 min at 400°C.