Development of noble metal nano-composite electrode for gas sensors

气体传感器用贵金属纳米复合电极的研制

基本信息

批准号：
13555184
负责人：
GOTO Takashi
金额：
$ 5.12万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

项目摘要

Noble metal(Ir or Ru) nano-composite films were synthesized by chemical vapor deposition using beta-diketonato complexes as precursors, and their microstructures and electrode properties for gas sensors were studied. Ir-YSZ nano-composite electrodes consisted of amorphous YSZ and Ir particles of 5-10 nm in diameter. The interfacial conductivity for the Ir-YSZ electrodes was almost 1000 times higher than that of sputtered-Pt electrodes due to large contact area between YSZ and Ir in nano-composite electrodes and high catalytic activity of Ir nano-particles. The electro-motive-force values of the oxygen concentration cell constructed from the Ir-YSZ electrodes and YSZ electrolyte showed the Nernstian theoretical values and the response time was 10-20s at 650℃. Ir-C and Ru-C nano-composite films containing about 50 vol% of carbon were prepared by MOCVD, and their microstructures and electrode properties were investigated. Ir or Ru particles of 5-20 nm in diameter were dispersed in amorphous C matrix. The AC conductivities associating to the interface charge transfer between 1r-C or Ru-C composite electrode and YSZ electrolyte were 100-1000 times higher than that of Pt electrodes. The emf values of the oxygen gas concentration cell constructed from the nano-composite electrodes and YSZ electrolyte showed the Nernstian theoretical values at low temperatures around 500 K. The response time of the concentration cell was 110 s at 550 K for Ir-C and 900 s at 500 K for Ru-C nano-composite electrodes.

以β-二酮配合物为前驱体，采用化学气相沉积法合成了贵金属（Ir或Ru）纳米复合薄膜，并研究了由非晶YSZ和Ir组成的Ir-YSZ纳米复合电极的微观结构和电极性能。直径为 5-10 nm 的 Ir-YSZ 电极的界面电导率几乎比溅射 Pt 高 1000 倍。由于纳米复合电极中 YSZ 和 Ir 之间的大接触面积以及 Ir 纳米颗粒的高催化活性，由 Ir-YSZ 电极和 YSZ 电解质构建的氧浓差电池的电动势值显示。含约50vol%的Ir-C和Ru-C纳米复合薄膜的能斯特理论值和响应时间为10-20s。采用MOCVD法制备了碳，并研究了它们的微观结构和电极性能，直径为5-20 nm的Ir或Ru颗粒分散在非晶C基体中，其交流电导率与1r-C或Ru-C之间的界面电荷转移有关。由纳米复合电极和YSZ电解质构建的氧气浓差电池的电动势值比Pt电极高100-1000倍。 YSZ电解质在500 K左右的低温下表现出能斯特理论值。浓差池的响应时间对于Ir-C在550 K为110 s，对于Ru-C纳米复合电极在500 K为900 s。