Yomogida Yohei, Liu Zheng, Ichinose Yota, Yanagi Kazuhiro
Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0364, Japan.
National Institute of Advanced Industrial Science and Technology (AIST), Nagoya, Aichi 463-8560, Japan.
ACS Omega. 2018 Aug 10;3(8):8932-8936. doi: 10.1021/acsomega.8b00745. eCollection 2018 Aug 31.
Tungsten disulfide (WS) nanotubes are cylindrical, multiwall nanotubes with various diameters and wall numbers. They can exhibit various unique properties depending on their structures and thus preparing samples with uniform structures is important for understanding their basic properties and applications. However, most synthesis methods have difficulty to prepare uniform samples, and thus, a purification method to extract nanotubes with a selected diameter and wall number must be developed. Here, we demonstrate a solution-based purification of WS nanotubes using a surfactant solution. Stable dispersions of nanotubes were prepared using nonionic surfactants, which enabled us to sort the diameters and wall numbers of the nanotubes through a centrifugation process. By optimizing the conditions, we successfully obtained thin nanotubes with a mean diameter of 32 nm and mean wall number of 13 with relatively small distributions. Finally, we clarified the relationships between the structure and optical properties of the nanotubes.
二硫化钨（WS）纳米管是具有不同直径和壁数的圆柱形多壁纳米管。它们可根据其结构展现出各种独特性质，因此制备具有均匀结构的样品对于理解其基本性质和应用很重要。然而，大多数合成方法难以制备出均匀的样品，所以必须开发一种用于提取具有选定直径和壁数的纳米管的纯化方法。在此，我们展示了一种使用表面活性剂溶液对WS纳米管进行基于溶液的纯化方法。使用非离子表面活性剂制备了纳米管的稳定分散体，这使我们能够通过离心过程对纳米管的直径和壁数进行分类。通过优化条件，我们成功获得了平均直径为32纳米且平均壁数为13、分布相对较小的细纳米管。最后，我们阐明了纳米管的结构与光学性质之间的关系。
