Osada Yuga, Teshima Sayaka, Munakata Hirokazu, Yanagishita Takashi
Department of Applied Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo 192-0397, Japan.
Langmuir. 2024 Aug 8. doi: 10.1021/acs.langmuir.4c02517.
An anodic oxide film with a regular pore arrangement was formed by the two-step anodization of an austenitic stainless steel (JIS SUS304) substrate. In this study, we determined the anodization conditions under which the pore arrangement in the anodic oxide film became self-organized. After removing the anodic oxide film formed by the first anodization with a mixture containing CrO and HF, the residual substrate was anodized under the same conditions as those in the first anodization. As a result, we found that it was possible to form an anodic oxide film with pores arranged in a regular pattern from the surface to the bottom. This is the first report on the formation of anodic oxide films with ordered nanohole array structures by the two-step anodization of austenitic stainless steel. The interpore distance of the resulting nanohole array structures can be controlled by changing the anodization conditions. By measuring the capacitance of the anodic oxide film, we confirmed that its properties depended on the heat-treatment temperature and pore depth. In addition, no significant decrease in the capacity of anodic oxide films with ordered nanohole array structures was observed, even when the scan rate of the cyclic voltammogram measurement was increased. This is considered to be because the cylindrical pores facilitate ion diffusion to the bottom of the holes. Anodic oxide films obtained by the anodization of austenitic stainless steel substrates can be applied as electrodes for capacitors.
通过对奥氏体不锈钢（JIS SUS304）基底进行两步阳极氧化，形成了具有规则孔排列的阳极氧化膜。在本研究中，我们确定了阳极氧化膜中孔排列实现自组织的阳极氧化条件。在用含有CrO和HF的混合物去除第一次阳极氧化形成的阳极氧化膜后，对残留的基底在与第一次阳极氧化相同的条件下进行阳极氧化。结果，我们发现有可能形成从表面到底部孔呈规则排列的阳极氧化膜。这是关于通过奥氏体不锈钢的两步阳极氧化形成具有有序纳米孔阵列结构的阳极氧化膜的首次报道。所得纳米孔阵列结构的孔间距可通过改变阳极氧化条件来控制。通过测量阳极氧化膜的电容，我们证实了其性能取决于热处理温度和孔深度。此外，即使增加循环伏安图测量的扫描速率，具有有序纳米孔阵列结构的阳极氧化膜的电容也没有显著降低。这被认为是因为圆柱形孔有利于离子扩散到孔底部。通过奥氏体不锈钢基底阳极氧化获得的阳极氧化膜可作为电容器的电极应用。
