定制用于高温电化学气体传感器的纳米氧化钽的结构和微观结构特性。

Tailoring the structural and microstructural properties of nanosized tantalum oxide for high temperature electrochemical gas sensors.

作者信息

Bonavita Anna, Di Bartolomeo Elisabetta, Chevallier Laure, D'Ottavi Cadia, Licoccia Silvia, Traversa Enrico

机构信息

Department of Chemical Science and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.

出版信息

J Nanosci Nanotechnol. 2009 Jul;9(7):4430-6. doi: 10.1166/jnn.2009.m72.

DOI:10.1166/jnn.2009.m72

PMID:19916469

Abstract

Ta2O5 nanopowders to be used as sensing electrodes in high temperature electrochemical gas sensors for hydrocarbons detection were synthesized using a sol-gel method and their structural and microstructural properties were investigated. The as-synthesized powders were heated at different temperatures in the range 250-1000 degrees C and characterized by TG-DTA, XRD, SEM, TEM and FT-IR. This investigation allowed to identify the correct thermal treatments to achieve the microstructural, textural and functional stability of materials working at high temperature, preserving their nano-metric grain size. Planar sensors fabricated by using Ta2O5 powders treated at 750 degrees C showed promising results for the selective detection of propylene at high temperature (700 degrees C). The good stability of the sensing response after gas exposure at high temperature was correlated to the stable microstructure the electrodes. Thus, Ta2O5 powders seems good candidate as sensing electrode for sensors for automotive exhausts monitoring.

摘要

采用溶胶 - 凝胶法合成了用于高温电化学气体传感器中检测碳氢化合物的五氧化二钽纳米粉末，并对其结构和微观结构特性进行了研究。将合成后的粉末在250 - 1000摄氏度范围内的不同温度下加热，并通过热重 - 差示热分析（TG - DTA）、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和傅里叶变换红外光谱（FT - IR）进行表征。该研究确定了正确的热处理方法，以实现材料在高温下工作时的微观结构、织构和功能稳定性，同时保持其纳米级晶粒尺寸。使用在750摄氏度下处理的五氧化二钽粉末制造的平面传感器，在高温（700摄氏度）下对丙烯的选择性检测显示出有前景的结果。高温气体暴露后传感响应的良好稳定性与电极稳定的微观结构相关。因此，五氧化二钽粉末似乎是用于汽车尾气监测传感器的传感电极的良好候选材料。