Development of Ambient Temperature, Solid-State Oxygen Sensors Based on Limiting Current Using Superionic Conductors
Project/Area Number |
07651005
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
工業物理化学
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Research Institution | Science University of Tokyo |
Principal Investigator |
KUWANO Jun Science University of Tokyo, Department of Engineering, Research Associate, 工学部, 助手 (70084390)
|
Project Period (FY) |
1995 – 1996
|
Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
|
Keywords | Oxygen sensor / Ionic conductor / Fluoride / Ambient temperature / Solid-state / 酸素 / 固体電解質 / 固体センサ / 電気化学センサ |
Research Abstract |
There are strong demand for development of solid-state sensors permitting measurements of O_2 concentration under diversified conditions. In this study, amperometric sensors (Ag|Ag_6I_4WO_4|PbSnF_4・insulating material (IM) mixture|sensing electrode (SE) mixture) using superionic conductors were made, and the effects of the constituents of SE and the electrolyte mixtures on response properties and the mechanims of the fast response were examined. 1) Effects of the PbSnF_4・IM mixture : The short-circuit-current, Isc, decreased with increasing amount of IM (polymers, oxides, phthalocyanine : Pc) and the response time t_<90> was improved 1/10-1/2.2) Roles of Pc in the response mechanism : For all the SE containing Pc, Isc varied linearly with Po_2. The Pc was found to play the role of the catalysis of two-electron reduction as well as the role described above. 3) Effects of the electronic conductive materials (EC) : The response properties did not depend on the chemical and physical proper
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ties of EC incorporated into SE.Exceptionally the incorporation of whisker materials resulted in the fastest t_<90> of those of this type of known sensors. 4) Mechanism of the fast response : The ECs that fulfilll four requirements, (1) aspect ratios of 5-20 (2) smooth surface (3) high conductivity (4)length of 10-30 m^<-6>, form conductive network in SE.O_2 defuse easily along the surface and electrons readily move through the network, thereby the reduction sites (three-phase boundaries) located only on the network are rapidly uniformed chemically and physically. This leads to rapid response. 5) The present situation and problems awaiting solution : The sensors can work in an operating pressure range of 2kPa-10MPa and down to 5゚C.t_<90> reach a practical level. CO_2 gas dose not interfere up to Pco2=500kPa, but humidity bring an error. The suppression of this interference and the reexamination of the stability and reproducibility are required towards the practical use. The concept established here is applicable to improvements of other gas sensors including CO_2 sensors. Less
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Report
(3 results)
Research Products
(21 results)