CuFe2O4敏感电极微观结构对电势型氨传感器氨气响应性能的影响

Effect of CuFe2O4 Sensing Electrode Microstructure on NH3 Sensing Characteristics for a Potentiometric Ammonia Sensor

以CuFe2O4为敏感电极,YSZ为固体电解质的电势型气体传感器被制备用于汽车尾气中氨气浓度的检测。CuFe2O4被溶胶-凝胶法制备并在900℃煅烧获得。通过分别在950℃、1000℃和1050℃烧结获得了具有不同微观结构的CuFe2O4敏感电极,并在650℃评估了它们的氨气响应性能,发现电极微观结构对响应性能有较大影响。1000℃烧结传感器的氨敏感度最高,其值为-68.5 mV/decade,对320×10^-6和20×10^-6浓度的氨气的响应信号值分别高达-92.3 mV和-8.3 mV。它的优异性能与SEM和BET结果显示的它具有最多的TPB数量,适中的电极厚度和孔隙率有关,也通过EIS和极化测试被证实。传感器也拥有较好的氨气选择性和长期稳定性,表明CuFe2O4在电势型NH3传感器的实际应用中具有较好的潜力。

Potentiometric gas sensor with CuFe2O4 as the sensing electrode and YSZ as the solid electrolyte was prepared for the detection of ammonia concentration in automobile exhaust.CuFe2O4 was prepared by sol-gel method and calcined at 900℃.CuFe2O4 sensing electrodes with different microstructures were obtained by sintering at 950℃,1000℃and 1050℃,respectively,and their NH3 response characteristics were evaluated at 650℃.It was observed that the electrode microstructure has great influence on the response performance.The 1000℃sintered sensor presents the highest NH3 sensitivity of-68.5 mV/decade,it has the response values of-92.3 mV and-8.3 mV to 320×10-6 and 20×10-6 NH3,respectively.Its good performance was related to the most TPB sites,moderate electrode thickness and porosity from the results of SEM and BET,it was also confirmed by EIS and polarization test.The sensor also has good ammonia selectivity and long-term stability,indicating that CuFe2O4 has good potential in the practical application of the potentiometric NH3 sensor.