Surface Defects as a Tool to Solubilize and Functionalize WS₂ Nanotubes

Layered transition metal dichalcogenides contain a number of crystal defects that significantly change their properties and are beneficial or detrimental for a specific application. We have prepared defect-rich multiwalled WS₂ nanotubes by reductive sulfidization of W₁₈O₄₉ nanowires that were obtained solvothermally from tungsten chloride in different alcohols. The synthesis of the W₁₈O₄₉ nanowires was monitored, and their morphological characteristics (e.g., length, rigidity, and aspect ratio) are described in detail. The effect of the morphology of the nanowires on the synthesis of WS₂ nanotubes was investigated in order to obtain WS₂ nanotubes that are highly solvent-dispersible. Dispersions of the WS₂ nanotubes in organic solvents are very stable for several days. The nanotubes were easily functionalized with noble metal, metal oxide, and Janus-type metal@metal oxide nanoparticles. The synthesis of nanowires and nanotubes and the immobilization of the nanoparticles were demonstrated by TEM, high-resolution TEM (HRTEM) combined with energy-dispersive X-ray spectroscopy (EDX), electron diffraction (ED), XRD, and Raman spectroscopy.