Nanotubes of WS 2 have indeed been produced and characterized by Tenne and co-workers in 1992. A facile, large-scale and low-cost route was used to synthesize the nano tubes of WS 2 nanoparticles by following the decomposition of WS 3 . We therefore decided to examine the transformation of WS 3 at high temperatures in a hydrogen atmosphere. Having succeeded in obtaining WS 2 nanotubes by this means, we sought to prepare these nanotubes by hydrogen treatment of ammonium thiomolybdate which is the precursor of WS 3 . WS 3 was prepared by the thermal decomposition of (NH 4 ) 2 WS 4 at 450 C in a nitrogen atmosphere. The WS 3 so obtained was X-ray amorphous. Heating WS 3 in a stream of H 2 at 800-1100 gave an excellent yield of WS 2 nanotubes. The as-synthesized nanotubes of WS 2 are of tube structure with an average size of about 6-18 nm. The composition, morphology and structure of the products were characterized by XRD, SEM, and Edax. The influences of the main reaction conditions were investigated and the possible growth mechanisms are proposed. Furthermore, the as synthesized nanotubes have many applications such as lubricants, catalysts, hydrogen storage bodies, super shock absorbers. Particularly in the field of lubrication, ultralow-friction properties have been observed when WS 2 materials were used as solid lubricants, which made them become one of the focuses of research. Key Words Nanotube, WS 2 , Lubricant, Catalyst, Scanning Electron Microscopy
