High sensitivity and selectivity of mixed potential sensor based on Pt/YSZ/SmFeO3 to NO2 gas

• Published in: Sensors and actuators. B, Chemical Chemical, 2013-07, Vol.183, p.550-555
• Main Authors: Giang, Ho Truong, Duy, Ha Thai, Ngan, Pham Quang, Thai, Giang Hong, Thu, Do Thi Anh, Thu, Do Thi, Toan, Nguyen Ngoc
• Format: Article
• Language: English
• Subjects: catalytic activity; ceramics; crystal structure; dielectric spectroscopy; electrochemistry; electrolytes; methane; Mixed potential gas sensors; nitrogen dioxide; sol-gel processing; Solid electrolyte; temperature; X-ray diffraction; Yttria-stabilized zirconia
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2013.04.035

Yttria-stabilized zirconia (YSZ) ceramic has been well known as a solid electrolyte in electrochemical gas sensors working at high temperature. In this work, YSZ-8 (ZrO2 doped 8mol% Y2O3) powder was synthesized by a sol–gel method. Crystalline structure of the synthesized powder YSZ-8 was analyzed by X-ray diffraction. The impedance spectroscopy investigation showed that the pressed plate YSZ-8 sintered at 1300°C had good ionic conductivity at high working temperature. The gas sensing properties of the mixed potential sensor Pt/YSZ-8/SmFeO3 were investigated by exposing to NO2, CO, CH4, C3H8 and C6H14 at the operating temperatures from 300 to 500°C. The experimental results indicated that the sensor Pt/YSZ-8/SmFeO3 presented very good sensitivity and selectivity to NO2 gas. The high sensitivity of the sensor Pt/YSZ-8/SmFeO3 to NO2 was suggested by relation to high catalytic activity of the oxide SmFeO3 to NO2.