【摘要】 采用自蔓延燃烧（SHS）法合成了纳米敏感材料一氧化铟（In₂O₃）,以氧化钇稳定的氧化锆（YSZ）为固体电解质，铂（Pt）为参比电极，制备了混合电位型氨气（NH₃）传感器。采用X射线衍射（XRD）、扫描电镜（SEM）和透射电子显微镜（TEM）对敏感电极形貌进行表征。研究发现，随着电极厚度的增加，更多的NH₃被吸附到表面参与电化学过程，传感性能增强；若电极层过厚，大部分NH₃在穿过电极层到达三相界面（TPB）区域之前，被气固多相催化反应消耗，传感性能降低；SEM表征结果显示，最优的电极厚度为104.20μm。同时研究了粒径对性能的影响，在煅烧温度为900℃时，传感器表现出最高的灵敏度（-64.20 mV/decade）,TEM表征结果显示，此时晶粒的平均粒径为75.92 nm。通过极化曲线测试验证了传感器响应机理符合混合电位理论。更多还原

【Abstract】 Nano sensing material In₂O₃ is prepared using self-propagation high-temperature synthesis（SHS）method for fabricating sensing electrodes of mixed potential type NH₃ sensors adopting yttria-stabilized zirconia（YSZ）as solid electrolyte and Pt as reference electrode.Morphology of the sensing electrode samples are characterized using XRD,SEM and TEM.It is found through research that as the electrode thickness increasing, more NH₃ molecules are absorbed onto the surface of the electrode to participate in electrochemical processes, so that the sensing performance is increased.However, the sensing performance is suppressed if the sensing electrode layer is too thick, because most NH₃ molecules are consumed by the gas-solid heterogeneous catalytic reactions before they can penetrate the electrode layer and reach the three-phase boundary（TPB）region.The SEM characterization results show that the optimum thickness of the sensing electrode layer is 104.20 μm.At the same time, effect of particle size on performance is researched.It is found that at calcination temperature of 900 ℃,the sensor shows the highest sensitivity（-64.20 mV/decade）.The TEM characterization results show that the average particle size of the crystal particles at 900 ℃ is 75.92 nm.The polarization curve test verifies that the sensor response mechanism conforms to the mixed potential theory.更多还原