Synthesis of bulk WS2 nanotube phases

The synthesis of a pure phase of very long and hollow WS, nanotubes from sh ort but asymmetric oxide nanoparticles is described. In this process, the o xide nanoparticles grow along their longest axis; and subsequently their ou termost layer is being sulfidized, while the growing oxide tip remains unco ated as long as the nanowhisker continues to grow. Thereafter, the sulfide cup is closed and a slow diffusion controlled sulfidization of the oxide co re is completed within 60-120 min.