A mixed-potential type NH₃ sensor equipped with CuFe₂O₄ and SnO₂@CuFe₂O₄ sensing electrode is presented. The CuFe₂O₄ spinel-oxide and SnO₂@CuFe₂O₄ composites were synthesized by a modified-Pechini route. The electrode materials were characterized for the physical properties by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS) analysis. It was found that the sensing characteristics were critically dependent on the extent of Triple-phase boundary (TPB) lengths and operating conditions of the sensor. Furthermore, the sensing performance of CuFe₂O₄ spinel-oxide was enhanced by compositing with SnO₂ nanocrystals resulting in a synergistically enhanced response (ΔV) of −40 mV towards 80 ppm NH₃, almost double and quadruple of the response of bare CuFe₂O₄ and SnO₂ electrodes at 650 ℃, respectively. The sensor also displayed excellent stability towards oxygen and humidity variations, along with low cross-sensitivities towards interfering gases; e.g. NO, CO, CH_4, and NO₂. The complex impedance spectra (EIS) and dc polarization (I-V) measurements were performed for an insightful analysis of the sensing mechanism conforming to the mixed-potential model.

的混合电位型NH ₃传感器配备的CuFe ₂ ö ₄和SnO ₂ @CuFe ₂ ö ₄感测电极被呈现。所述的CuFe ₂ ö ₄尖晶石氧化物和SnO ₂ @CuFe ₂ ö ₄通过修改的Pechini路线合成了复合材料。通过粉末X射线衍射（XRD），X射线光电子能谱（XPS），扫描电子显微镜（SEM）和能量色散能谱（EDS）分析来表征电极材料的物理性能。已经发现，感测特性主要取决于三相边界（TPB）长度的范围和传感器的工作条件。此外，通过与SnO ₂纳米晶体复合提高了CuFe ₂ O ₄尖晶石氧化物的感测性能，导致对80 ppm NH ₃的协同响应增强（ΔV）为-40 mV ，几乎是裸CuFe响应的两倍和四倍₂ Ø_4个电极和650℃的SnO ₂电极。该传感器还显示出对氧气和湿度变化的出色稳定性，以及对干扰气体的低交叉敏感性。例如，NO，CO，CH ₄和NO ₂。进行了复数阻抗谱（EIS）和直流极化（IV）测量，以便对符合混合电位模型的传感机制进行深入分析。