A study on the application of V2O5/WO3/TiO2 (VWT) as the sensitive material for resistive-type SO2 sensor was conducted, based on the fact that VWT is a well-known catalyst material for good selective catalytic nitrogen oxide reduction with a proven excellent durability in exhaust gases. The sensors fabricated in this study are planar ones with interdigitated electrodes of Au or Pt. The vanadium content of the utilized VWT is 1.5 or 3.0 wt%. The resistance of VWT decreases with an increasing SO2 concentration in the range from 20 ppm to 5,000 ppm. The best sensor response to SO2 occurs at 400 °C using Au electrodes. The sensor response value is independent on the amount of added vanadium but dependent on the electrode materials at 400 °C. These results are discussed and a sensing mechanism is discussed.
For high temperature application, a planar SO 2 sensor using NASICON as an electrolyte and V 2 O 5 /WO 3 /TiO 2 + Au or Pt as a sensing electrode was fabricated and investigated. In the case of Pt electrodes, the sensor showed the strange response in temperature range from 300600°C. In the case of Au electrodes, the sensor showed a strange behavior at 300 and 400°C, while at 600°C the sensor showed good response to SO 2 . The highest sensitivity with 8083 mV/decade in the SO 2 range from 20 to 200 ppm was observed at 600°C, although offset shifting was observed in repeated measurements. The sensors showed the potential for good selectivity at 600°C in the case of Au electrodes. The fact that the electric potential difference of the sensor is strongly affected by the electrode materials may intend that the mechanism of the sensor is a mixed potential type.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.