Selective Synthesis of Hollow and Filled Fullerene-like (IF) WS2 Nanoparticles via Metal–Organic Chemical Vapor Deposition

The synthesis of WS 2 onion-like nanoparticles by means of a high-temperature metal–organic chemical vapor deposition (MOCVD) process starting from W(CO) 6 and elemental sulfur is reported. The reaction can be carried out as a single-step reaction or in a two-step process where the intermediate products, amorphous WS 2 nanoparticles, formed through the high-temperature reaction of tungsten and sulfur in the initial phase of the reaction, are isolated and converted into onion-type WS 2 nanoparticles in a separate annealing step. Analysis of the reaction product using X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) combined with energy dispersive X-ray spectroscopy (EDX) allowed to optimize the reaction in such a way that filled onion-like structures are formed in a one-step reaction, whereas hollow onion-like structures are obtained by the two-step procedure. A model could be devised that allows us to rationalize the different outcome of the reactions. The MOCVD approach therefore allows a selective synthesis of open and filled fullerene-like chalcogenide nanoparticles.