Effects of composition and structure of sensing electrode on NO2 sensing properties of mixed potential-type YSZ-based gas sensors
Effects of composition and structure of sensing electrode on NO2 sensing properties of mixed potential-type YSZ-based gas sensors
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DOI：
10.1016/j.snb.2016.06.103
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发表时间：
2016-12
影响因子：
8.4
通讯作者：
T. Ueda;Miyuki Sakai;K. Kamada;T. Hyodo;Y. Shimizu
中科院分区：
文献类型：
--
作者：
T. Ueda;Miyuki Sakai;K. Kamada;T. Hyodo;Y. Shimizu
NO2sensing properties of yttria-stabilized zirconia (YSZ)-based gas sensors attached with various kinds of single-layered or NiO-based hetero-layered sensing electrodes (SE) have been examined in the operating temperature range of 500 ∼ 800 °C. Although a sensor with a small-area Pt SE showed negligible NO2response at 600 °C, the lamination with a large-area NiO layer on the small-area Pt SE improved the NO2response. In addition, the lamination with the large-area NiO layer on small-area Pt-NiO, Au or ZnO SE showed rather large NO2response. Among all sensors tested, the sensor with the small-area Au SE laminated with the large-area NiO layer showed the largest NO2response (ca. 49.1 mV to 80 ppm NO2at 600 °C). The electrochemical impedance properties of the sensor with the small-area Au SE showed larger charge transfer resistance (namely, lower electrocatalytic activity) for oxygen redox reaction than that of the sensor with the small-area Pt SE. In addition, the total of charge transfer resistance of the sensor with the small-area Au SE laminated with the large-area NiO layer decreased upon exposure to NO2due to the simultaneous occurrence of NO2reduction reaction. These results indicate that the large NO2response of the sensor with the small-area Au SE laminated with the large-area NiO layer is caused by the high electrochemical activity of NO2reduction reaction at the interface of NiO/YSZ and the low electrochemical activity for the oxygen redox reaction at Au/YSZ/gas triple phase boundaries.
