NiO电极中YSZ添加量对NO_x传感器气敏性能的影响

Affection of YSZ Amount in NiO Electrode to the Gas-Sensing Properties of NO_x Sensor

以钇稳氧化锆(简称YSZ,Yttria-Stabilized Zirconia)为固体电解质,添加不同摩尔比例YSZ的NiO+YSZ混合体为敏感电极材料,通过丝网印刷技术制备了相应的混合电势型NOx传感器。采用XRD和SEM手段对NiO混合物进行了物理性能分析,利用电势和阻抗测量设备对传感器样品的输出电势(EMF)和交流阻抗等电学参数随NO浓度的变化进行了研究。结果显示:NiO+YSZ的混合体中,物相独立,没有新相产生;在相同NO检测环境下,敏感电极中YSZ所占摩尔比例为20mol%时传感器的响应电势最大且在0.01 Hz～100 kHz范围内的阻抗谱最小,SEM也显示此时具有很好的TPB。

Several mixed-potential-type NOx sensors were prepared by means of screen-printing technique using yttria-stabilized zirconia（8YSZ,8mol% Y2O3 doped）as electrolyte and some powders obtained by the NiO mixed with different proportion of YSZ as electrode material.The physical characteristics of sensors was analyzed by X-ray diffraction（XRD）and scanning electron microscope（SEM）.Dependences of electromotive force（EMF）and complex impedance on the NOx concentration were studied by corresponding testing equipments,respectively.The results showed that the phase of NiO or YSZ is single and no new phase is formed;under the same testing environment containing NO,the potential response of the sensor is maximum and the impedance of that in the context of 0.01 Hz^100 kHz is minimum when the molar ratio of YSZ share 20mol% in sensitive electrode,SEM also shows a very good three-phase interface at the same time.