Details

Autor(en) / Beteiligte

• Kreizman, Ronen
• Enyashin, Andrey N.
• Deepak, Francis Leonard
• Albu-Yaron, Ana
• Popovitz-Biro, Ronit
• Seifert, Gotthard
• Tenne, Reshef

Titel

Synthesis of Core-Shell Inorganic Nanotubes

Ist Teil von

• Advanced functional materials, 2010-08, Vol.20 (15), p.2459-2468

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2010

Quelle

Wiley Online Library

Beschreibungen/Notizen

• New materials and techniques pertaining to the synthesis of inorganic nanotubes have been ever increasing since the initiation of the field in 1992. Recently, WS2 nanotubes, which are produced now in large amounts, were filled with molten lead iodide salt by a capillary wetting process, resulting in PbI2@WS2 core–shell nanotubes. This work features progress in the synthesis of new core–shell nanotubes, including BiI3@WS2 nanotubes produced in a similar same manner. In addition, two new techniques for obtaining core–shell nanotubes are presented. The first is via electron‐beam irradiation, i.e., in situ synthesis within a transmission electron microscope. This synthesis results in SbI3 nanotubes, observed either in a hollow core of WS2 ones (SbI3@WS2 nanotubes), or atop of them (WS2@SbI3 nanotubes). The second technique involves a gaseous phase reaction, where the layered product employs WS2 nanotubes as nucleation sites. In this case, the MoS2 layers most often cover the WS2 nanotube, resulting in WS2@MoS2 core–shell nanotubes. Notably, superstructures of the form MoS2@WS2@MoS2 are occasionally obtained. Using a semi‐empirical model, it is shown that the PbI2 nanotubes become stable within the core of MoS2 nanotubes only above a critical core diameter of the host (>12 nm); below this diameter the PbI2 crystallizes as nanowires. These model calculations are in agreement with the current experimental observations, providing further support to the growth mechanism of such core–shell nanotubes. A core–shell inorganic nanotubular structure is synthesized applying a WS2 nanotube as a template. The guest material, in this case MoS2, can be distinguished in the TEM from its host material (template) by its contrast and inter‐layer distance. Chemical analysis tools (e.g., EDS and EELS) are also utilized to confirm the presence of guest elements.