Abstract The SmMn2O5 was prepared by sol-gel method and characterized by X-ray diffraction, BET and scanning electron microscope. A potentiometric methane sensor was fabricated at the sintering temperature of 900 °C by using SmMn2O5 as sensing electrode and YSZ as solid electrolyte. The response signal for different concentrations of methane was tested at 350–500 °C. With the increase of operating temperature from 350 °C to 500 °C, the methane sensitivity decreases gradually from −47.97 mV/decade to −13.96 mV/decade, meanwhile the response and recovery rates accelerate. At the optimal operating temperature of 400 °C, the response and recovery times are significantly shortened to 27 s and 33 s for 400 ppm CH4, respectively, while the sensitivity is only reduced slightly to −44.50 mV/decade. The linear relationship between the response values and the logarithm of CH4 concentration confirms the mixed potential mechanism of the prepared sensor. The sensor attached with SmMn2O5-SE has a good CH4 selectivity with small cross sensitivity to C3H8 and CO2, and it also shows good reproducibility and long-term stability, which indicate that there is a potential for SmMn2O5 to the methane leakage warning.

中文翻译：

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基于SmMn2O5传感电极的用于甲烷检测的电位传感器

摘要 采用溶胶-凝胶法制备了SmMn2O5，并通过X射线衍射、BET和扫描电子显微镜对其进行了表征。通过使用 SmMn2O5 作为传感电极和 YSZ 作为固体电解质，在 900 °C 的烧结温度下制造了电位甲烷传感器。在 350–500 °C 下测试了不同浓度甲烷的响应信号。随着工作温度从350°C升高到500°C，甲烷灵敏度从-47.97 mV/decade逐渐降低到-13.96 mV/decade，同时响应和回收率加快。在 400 °C 的最佳工作温度下，400 ppm CH4 的响应和恢复时间分别显着缩短至 27 s 和 33 s，而灵敏度仅略微降低至 -44.50 mV/decade。响应值与 CH4 浓度对数之间的线性关系证实了所制备传感器的混合电位机制。附有 SmMn2O5-SE 的传感器具有良好的 CH4 选择性，对 C3H8 和 CO2 的交叉敏感性小，并且还表现出良好的重现性和长期稳定性，这表明 SmMn2O5 具有甲烷泄漏预警的潜力。