Chemical synthesis of molybdenum disulfide nanoparticles in an organic solution

Molybdenum disulfide, MoS2, nanoparticles can be synthesized either at high temperature as mono- and polycrystalline materials or at low temperature using various (electro)chemical routes. In the work presented, MoS2 nanoparticles were obtained using a low temperature (140 degreesC) method via a chemical solution reaction route between the organometallic precursor Mo(CO)(6) and sulfur in p-xylene. As obtained, the MoS2 nanoparticles of 10-30 nm diameter were mostly amorphous with a rounded shape. Upon annealing at 550 degreesC under vacuum, the nanoparticles lost their rounded shape and became slightly crystallized with curved (002) basal van der Waals planes (2H hexagonal structure). An increase of 2-4% in the d((002)) spacing or the annealed MoS2 nanoparticles compared to polycrystalline MoS2 was observed. The size and shape of these nanoparticles play an important role for their properties, e.g. in catalysis and lubrication.