Preparation of Single‐Crystal MoS2 Nanotubes and 1D Van der Waals Heterostructures

Abstract Single‐crystal MoS 2 nanotubes possess outstanding electronic and optoelectronic properties. However, previous attempts to synthesize MoS 2 nanotubes are hindered by poor crystallinity and the high strain energy required to roll a sheet with three atomic layers into a tubular structure. Here, the confined template growth of well‐crystallized MoS 2 nanotubes encapsulated within carbon nanotubes, forming 1D van der Waals heterostructures, is reported. The growth of MoS 2 nanotubes is catalyzed by iron carbide. CNTs serve as nanoreactors and structurally confined templates, ensuring the growth of fine MoS 2 nanotubes. Water vapor is employed to manipulate the structure and morphology of resultant MoS 2 . Free‐standing MoS 2 nanotubes are obtained by removing outer CNTs with gentle plasma etching. This method demonstrate the power of coupling the catalytic effect and the space confinement in the growth of high‐quality MoS 2 nanotubes, which may become a common strategy for the preparation of general 1D nanostructures of various transition metal dichalcogenides and other materials.