Room-Temperature Production of Nanocrystalline Molybdenum Disulfide (MoS) at the Liquid-Liquid Interface.

Scalable synthesis of 2D materials is a prerequisite for their commercial exploitation. Here, a novel method of producing nanocrystalline molybdenum disulfide (MoS) at the liquid-liquid interface is demonstrated by decomposing a molecular precursor (tetrakis(diethyldithiocarbamato) molybdenum(IV)) in an organic solvent. The decomposition occurs over a few hours at room temperature without stirring or the addition of any surfactants, producing MoS which can be isolated onto substrates of choice. The formation of MoS at the liquid-liquid interface can be accelerated by the inclusion of hydroxide ions in the aqueous phase, which we propose to act as a catalyst. The precursor concentration was varied to minimize MoS thickness, and the organic solvent was chosen to optimize the speed and quality of formation. The kinetics of the MoS formation has been investigated, and a reaction mechanism has been proposed. The synthesis method is, to the best of our knowledge, the first reported room-temperature synthesis of transition-metal dichalcogenides, offering a potential solution to scalable 2D material production.