Multifrequency nanoscale impedance microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes
Multifrequency nanoscale impedance microscopy (m-NIM): A novel approach towards detection of selective and subtle modifications on the surface of polycrystalline boron-doped diamond electrodes
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DOI：
10.1016/j.ultramic.2019.01.004
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发表时间：
2019-04-01
期刊：
影响因子：
2.2
通讯作者：
Ryl, Jacek
中科院分区：
文献类型：
--
作者：
Zielinski, Artur;Cieslik, Mateusz;Ryl, Jacek
在本文中，我们描述了纳米尺度阻抗显微镜（NIM）的改进，即将接触模式原子力显微镜与局部阻抗测量相结合。假设的方法是基于多频电压摄动的应用，而不是标准的逐频分析，它提供了更高的时间效率和准确的测定结果阻抗谱，具有高空间分辨率。通过适当的等效电路进行阻抗谱分析，可以绘制表面电阻和接触电容。以多晶掺重硼金刚石（BDD）电极为研究对象。最近的研究表明，这种电极暴露于氧化环境中可能会导致端型的改变，因此它是描述BDD电学和电化学性能的关键因素。我们成功地应用了多频NIM，证明了终止型的修饰是选择性的，并以不同的倾向发生在具有特定晶体取向的晶粒上。此外，我们的方法能够检测到由于各种氧化处理而产生的细微的亚微观表面非均质性，并将它们与与晶界处硼局部分布相关的表面非均质性区分开来。
In this paper, we describe the modification of Nanoscale Impedance Microscopy (NIM), namely, a combination of contact-mode atomic force microscopy with local impedance measurements. The postulated approach is based on the application of multifrequency voltage perturbation instead of standard frequency-by-frequency analysis, which among others offers more time-efficient and accurate determination of the resultant impedance spectra with high spatial resolution. Based on the impedance spectra analysis with an appropriate electric equivalent circuit, it was possible to map surface resistance and contact capacitance.Polycrystalline heavy boron-doped diamond (BDD) electrodes were the research object. Recent studies have shown that the exposure of such electrodes to oxidizing environment may result in the modification of termination type, and thus it is a key factor in describing the electric and electrochemical properties of BDD. We have successfully applied multifrequency NIM, which allowed us to prove that the modification of termination type is selective and occurs with different propensity on the grains having specific crystallographic orientation. Furthermore, our approach enabled the detection of even subtle submicroscopic surface heterogeneities, created as a result of various oxidation treatments and to distinguish them from the surface heterogeneity related to the local distribution of boron at the grain boundaries.