Sub-ppm H₂S sensor based on YSZ and hollow balls NiMn₂O₄ sensing electrode

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• 作者：Yingzhou Guan ; Chengguo Yin ; Xiaoyang Cheng ; Xishuang Liang ; Quan Diao ; Han Zhang ; Geyu Lu
• 关键词：Mixed-potential-type ; YSZ ; Solvent evaporation method ; H2S sensor
• 刊名：Sensors and Actuators B: Chemical
• 出版年：31 March, 2014
• 年：2014
• 卷：193
• 期：Complete
• 页码：501-508
• 全文大小：3542 K

文摘

A kind of mixed-potential-type gas sensor based on yttria stabilized zirconia (YSZ) and Nickel series spinel structure oxides electrode was designed for detection of low concentration hydrogen sulfide (H₂S). Among three oxides (NiMn₂O₄, NiCr₂O₄ and NiFe₂O₄) prepared by solvent evaporation method, hollow balls NiMn₂O₄ exhibited the highest sensitivity to H₂S gas in air at 500 掳C. Results of scanning electron microscope (SEM) and X-ray diffraction (XRD) revealed that micro-structure of materials could be influenced by the rate of reagent dropping in the solvent evaporating process and sintering temperature. Then, the relationship between sensing performance and micro-structure of NiMn₂O₄ was investigated. As a result, the sensor using NiMn₂O₄ with hollow balls (diameter 5-8 渭m) structure as the sensing electrode showed the best performance to 50 ppb to 2 ppm H₂S at 500 掳C. The 螖V value of the sensing device exhibited segmentally linear relationship to the logarithm of H₂S concentration and the slope was 鈭?5 mV/decade (50 ppb to 200 ppb) and 鈭?25 mV/decade (500 ppb to 2 ppm), respectively. The sensing device also showed an excellent selectivity. Finally, electrochemistry polarization curve measure was taken to further prove the mixed potential sensing mechanism.