Anenburg, Michael2020-03-171466-8033http://hdl.handle.net/1885/202349Various applications of transition metal dichalcogenides (TMDs) require preparation by exfoliation of precursor bulk materials. However, bulk TMDs are not always available in suitable forms and current synthesis methods may not result in appropriate crystals. This study reports synthesis of large crystals (50–100 μm) of MoS2 and ReS2, by recrystallisation of MoS2 powder or reaction of sulfate with perrhenic acid, respectively. The reactions have been performed at high pressure and temperature (≥1 GPa; ≥800 °C) in a liquid Ca-carbonate flux. The resulting crystals were characterised by electron microscopy imaging, EDS and WDS chemical analyses, and Raman spectroscopy. The carbonate matrix can be easily dissolved to recover the product TMDs. This method allows synthesis of large well-crystalline TMD compositions that are otherwise challenging to obtain.This research is supported by an Australian Government Research Training Program Scholarship and a Ringwood Scholarship. This work was supported by Australian Research Council grant FL130100066 to Hugh O'Neill who provided constructive comments on the manuscript.6 pagesapplication/pdfen-AU© The Royal Society of Chemistry 20192019-04-0810.1039/c9ce00188c2020-07-06