Cobalt-based solid reference-electrode usable in zirconia-based sensors for detection of oxygen or volatile organic compounds
Cobalt-based solid reference-electrode usable in zirconia-based sensors for detection of oxygen or volatile organic compounds
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DOI：
10.1016/j.snb.2014.07.072
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发表时间：
2014-11
影响因子：
8.4
通讯作者：
Yūki Tanaka;Tomoaki Sato;H. Ikeda;N. Miura
中科院分区：
文献类型：
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作者：
Yūki Tanaka;Tomoaki Sato;H. Ikeda;N. Miura
氧化钇稳定的氧化锆（YSZ）上形成的氧化物基电极的性能进行了评价作为固体参比电极（RE）。在所研究的各种电极中，通过将Co_3O_4涂覆在YSZ管的表面上，然后在1400 °C下烧结9小时而形成的Co_3O_4基电极被发现对0.05-21体积%（v/v）的响应不灵敏。在低于500 °C的操作温度下，对O2的响应和对各种气体（CO、NO、NO2、C3 H6、C3 H8、NH3、CH 4、H2;各100 ppm）的响应可忽略不计。EDX和XRD分析证实，Co 3 O 4层中的Co离子渗透到YSZ衬底中，并在YSZ中形成了固溶体。这似乎能够获得在YSZ上形成的Co 3 O 4基电极的上述气体不敏感性的能力。将本发明的Co 3 O 4基电极（RE）与Pt传感电极（SE）（或NiO-SE）结合，以制造YSZ基O2传感器（或挥发性有机化合物（VOC）传感器）。所获得的O2传感器的传感特性与使用Pt-SE和Pt/air-RE的传统O2传感器的那些相媲美。在这种情况下，计算出参与O2电化学反应的电子数（n）为4.1，这与理论值（n= 4.0）几乎相同。此外，所制造的VOC传感器甚至对10 ppb水平的甲苯（C7 H8）也给出了相对良好的感测特性。
The performance of oxide-based electrode formed on yttria-stabilized zirconia (YSZ) was evaluated as a solid reference-electrode (RE). Among the various electrodes examined, the Co3O4-based electrode which was formed by applying Co3O4on the surface of a YSZ tube and then sintered at 1400 °C for 9 h, was found to give insensitive response to 0.05–21 vol.% O2and negligible responses to various gases (CO, NO, NO2, C3H6, C3H8, NH3, CH4, H2; 100 ppm each) at the operational temperatures below 500 °C. EDX and XRD analysis confirmed that Co ion from the Co3O4layer penetrated to a YSZ substrate and formed a solid solution in YSZ. This seems to enable to attain the ability of the above-mentioned gas insensitivity of the Co3O4-based electrode formed on YSZ. The present Co3O4-based electrode (RE) was combined with Pt sensing-electrode (SE) (or NiO-SE), in order to fabricate a YSZ-based O2sensor (or a volatile organic compounds (VOCs) sensor). The sensing characteristics of the obtained O2sensor were comparable with those of a conventional O2sensor using Pt-SE and Pt/air-RE. In this case, the number (n) of electrons involving in the electrochemical reaction of O2was calculated as 4.1, which was almost same as the theoretical value (n= 4.0). In addition, the fabricated VOCs sensor gave relatively good sensing characteristics even to 10 ppb level of toluene (C7H8).