Core-Shell Nanotubes from Tungsten/Molybdenum Ditelluride-Tungsten Disulfide via Van der Waals Epitaxy

Tungsten ditelluride and molybdenum ditelluride in the form of nanotubes were materialized as core-shell structures with tungsten disulfide layers. The variability of the described protocols allows the formation of WS2@WTe2, reversed WTe2@WS2, and, by combining both approaches, multilayer WTe2@WS2@WTe2. Alternatively, WS2@MoTe2 or even WTe2@WS2@MoTe2 nanotubes were synthesized. Deposition of the telluride layers was achieved via Van der Waals epitaxial growth. Obtained nanostructures were characterized by advanced imaging techniques revealing structural composition hexagonal 2H and orthorhombic 1T’ for WS2 and WTe2 layers, respectively. In the case of MoTe2 nanotubes, the structural cascade of 2H-WS2@2H-MoTe2@1T’-MoTe2 was elucidated. Complex heterostructures were profoundly inspected by 4D scanning transmission electron microscopy position resolved diffraction, revealing their chiral nature. Mechanistic aspects of the synthesis were briefly studied. Moreover, tellurium-substituted WS2 nanotubes were synthesized and characterized. Importantly, WTe2 nanotubes contain inner tension due to layers bending that promise greatly modified electronic structure. Tungsten ditelluride-disulfide nanotubes complete the family of tungsten dichalcogenide nanotubular structures.