MoS2 nanoparticle precipitation in turbulent micromixers

Molybdenum sulfide nanoparticles (NP) have been successfully obtained, for lubricant applications, by means of a wet chemical synthesis in an aqueous solution employing ammonium molybdate, citric acid and ammonium sulfide as the reactants. Mo:citrate molar ratio and pH were optimized to control the phase and morphology of the final products. The production of MoS2 NP has then been performed in a micromixer, which has the feature of matching high degrees of reactant mixing, induced by the turbulent vorticous flow inside the precipitation chamber, and low residence times, which allow to suitably control the NP size. Remarkable MoS2 concentrations were obtained (around 20 wt.%), still being nanosized although loosely agglomerated, which lead to exceptional productivities per unit of reactor volume.

• The wet chemical synthesis of MoS2 nanoparticles has been performed in a micromixer.
• The NP size was controlled by varying the chemical and fluid-dynamic parameters.
• Loosely agglomerated nanoparticles with a mean size of 60 nm have been obtained.
• By controlling the reactant flow rate it was possible to cut by half the NP dimension.