Detection of VOC in air with a planar-type potentiometric gas sensor based on YSZ with a Pt electrode modified with TiO2
Detection of VOC in air with a planar-type potentiometric gas sensor based on YSZ with a Pt electrode modified with TiO2
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DOI：
10.1016/j.snb.2017.01.099
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发表时间：
2017-09
影响因子：
8.4
通讯作者：
Y. Sadaoka;M. Mori
中科院分区：
文献类型：
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作者：
Y. Sadaoka;M. Mori
用 TiO2 修饰的 Pt/YSZ 电极的半电池电势强烈依赖于空气中 VOC 的浓度。随着温度从 400 °C 升高到 600 °C，实验估计氧的能斯特关系中的电子数从 2.0 增加到 4.0。对于 400 °C 的 TiO2-Pt/YSZ 电极，提出了以下三个过程：[1] O2(gas)⇔ O2(ad)/TiO2、[2] O2(ad)/TiO2+ 2e−⇔ 2O−(ad)/TiO2 和 [3] 2O−(ad)/TiO2+ 2e−/Pt → 2O2−(ad)/Pt。 TiO2-Pt/YSZ 电极的半电池电势表示为 E = (RT/2F)ln[O2(ad)/TiO2]。使用氧气和VOC的混合物的竞争吸附模型以及吸附的VOC与吸附的氧气的氧化的组合来估计吸附的氧气的浓度。 TiO2-Pt/YSZ 电极的数值估计电势对于电势的 VOC 浓度依赖性在定性上是可靠的。采用原始 Pt 电极和采用 TiO2 修饰的电极的传感器的电极电位与空气中 VOC 的 ppm 水平相对应。
The half-cell potential of a Pt/YSZ electrode modified with TiO2was strongly dependent on the concentration of VOC in air. The experimentally estimated electron number in the Nernst relation for oxygen increased from 2.0 to 4.0 with increasing temperature from 400 to 600 °C. For the TiO2-Pt/YSZ electrode at 400 °C, the following three processes are proposed: [1] O2(gas)⇔ O2(ad)/TiO2, [2] O2(ad)/TiO2+ 2e−⇔ 2O−(ad)/TiO2, and [3] 2O−(ad)/TiO2+ 2e−/Pt → 2O2−(ad)/Pt. The half-cell potential of the TiO2-Pt/YSZ electrode is expressed as E = (RT/2F)ln[O2(ad)/TiO2]. The concentration of the adsorbed oxygen is estimated using a combination of a competitive adsorption model for a mixture of oxygen and VOC and oxidation of the adsorbed VOC with the adsorbed oxygen. Numerically estimated potentials of the TiO2-Pt/YSZ electrode are reliable qualitatively for the VOC concentration dependence of the potential. The electrode potential of the sensor with a pristine Pt electrode and the modified electrode with TiO2responded to the ppm level of VOCs in air.