Functional Design of Semiconductor Gas Sensors for Development of Odor Sensors

用于气味传感器开发的半导体气体传感器的功能设计

基本信息

批准号：
05555231
负责人：
EGASHIRA Makoto
金额：
$ 9.02万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05555231/
关键词：
Odor sensor Semiconductor gas sensor Trimethylamine Dimethylamine Ammonia Sensitizer Gas sensing mechanism

项目摘要

The present project was focused on functional design of semiconductorgas sensors for development of odor sensors capable of detecting of odor components, such as trimethylamine (TMA), dimethylamine (DMA) and ammonia, with high sensitivity and selectivity.Thickness dependence of TMA gas sensistvity of sensors equipped with interior electrodes have been investigated by employing semiconductor metal oxides loades with and without different amounts of noble metals. It has revealed that optimum design of both the thickness and the catalytic activity for TMA oxidation of sensor materials is of primary importance for the development of TMA gas sensors.It was found that In_2O_3-MgO (5mol%) loaded with 3.0 wt% Pt (3.0Pt/In_2O_3-MgO (5mol%)) was the only sensor which exhibited higher sensitivity to DMA than TMA at 300ﾟC,among the sensors tested. The DMA sensitivity was further enhanced by coating the surface of 3.0Pt/In_2O_3-MgO (5mol%) sensor with a TiO_2 or 0.5Pt/TiO_2 layr. The high DMA sensitivity of the single layr sensor was found to be attributed to its high activity for producing ethylenimine and less activity for producing NO_X. Ethylenimine produced during the oxidation of TMA is more reactive with chemisorbed oxygen on the sensor material, while NO_X are oxidation products of TMA and act as interference gases.High NH_3 sensitivity could be realized with the doible layr sensor consisting of an In_2O_3-MgO (5mol%) sensing layr, a 0.5Ir/TiO_2 coating layr atop the sensing layr and electrodes between these two layrs. It was found that selection of both the sensor materials having moderate NH_3 oxidation without producing large amounts of NO_X and the coating layr exhibiting high activity for reduction of NO_X into N_2 by NH_3 is of primary importance for developing an NH_3 sensor having high sensitivity.

本项目的重点是半导体气体传感器的功能设计，以开发能够检测气味成分的气味传感器，例如三甲胺（TMA）、二甲胺（DMA）和氨，具有高灵敏度和选择性。TMA气体灵敏度的厚度依赖性通过使用含有和不含有不同量的贵金属的半导体金属氧化物负载，对配备有内部电极的传感器进行了研究，结果表明，厚度和催化活性的最佳设计。传感器材料的TMA氧化对于TMA气体传感器的发展至关重要。研究发现负载3.0 wt% Pt的In_2O_3-MgO (5mol%) (3.0Pt/In_2O_3-MgO (5mol%))是唯一的传感器在测试的传感器中，在 300°C 下对 DMA 的灵敏度比 TMA 更高，通过对 DMA 进行表面涂层，DMA 灵敏度进一步提高。具有TiO_2或0.5Pt/TiO_2层的3.0Pt/In_2O_3-MgO(5mol%)传感器发现单层传感器的高DMA灵敏度归因于其产生乙烯亚胺的高活性和产生NO_X的活性。 TMA氧化过程中产生的NO_X与传感器材料上化学吸附的氧反应性更强，而NO_X则氧化由In_2O_3-MgO (5mol%)传感层、传感层顶部的0.5Ir/TiO_2涂层以及两层之间的电极组成的双层传感器可以实现高NH_3灵敏度研究发现，选择具有适度的NH_3氧化而不产生大量NO_X的传感器材料和表现出高还原活性的涂层NH_3将NO_X转化为N_2对于开发高灵敏度的NH_3传感器至关重要。