Effects of sintering temperature on the NH₃ sensing properties of Mg₂Cu_0.25Fe₁O_3.75 electrode for YSZ-based potentiometric NH₃ sensor

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• 作者：Xiangdong Li ; Chao Wang ; Bing Wang ; Yu Yuan ; Jinqiang Huang ; Haibo Zhang ; Feng Xia ; Jianzhong Xiao ; ^{jzxiao@mail.hust.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：A. Sintering ; Potentiometric NH3 sensor ; Mg2Cu0.25Fe1O3.75 ; YSZ ; SCO catalyst
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：1 February 2016
• 年：2016
• 卷：42
• 期：2
• 页码：2214-2220
• 全文大小：1877 K

文摘

Mg₂Cu_0.25Fe₁O_3.75 mixed metal oxides have been synthesized by a co-precipitation method for fabricating NH₃ sensors electrodes. The sensor electrodes were sintered at 1000 °C, 1100 °C, 1200 °C, and 1300 °C to obtain different electrode microstructures. The electrodes were characterized by X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method and Environmental Scanning Electron Microscope (ESEM). NH₃ response performances of the NH₃ sensors to different concentrations of test gases (20–400 ppm NH₃) were evaluated at 400 °C. The influences of sintering temperature on the microstructures, NH₃ sensing performances, and electrochemically catalytic activity of Mg₂Cu_0.25Fe₁O_3.75 electrodes were investigated. The electrode sintered at 1200 °C exhibited the biggest response (about 110 mV for 400 ppm NH₃) and the highest NH₃ sensitivity (72 mV/decade NH₃) of all the electrodes. Moreover, the response time and recovery time were within 8–4 s and 8–14 s, respectively. The enhanced NH₃ sensing performances of the Mg₂Cu_0.25Fe₁O_3.75 electrodes may be attributed to electrodes׳ larger electrochemically catalytic activity and more quantity of triple-phase boundary (TPB) of the sintered three-dimensional network electrode structure.