Influence of Process Parameters and Reducing Agent on the Size of MoS2 Nanoparticles Obtained in Impinging Jet Reactor

Abstract

Molybdenum disulfide (MoS2) is an emerging material with exciting properties. Many consider it an excellent catalyst, particularly for hydrogen evolution reaction. Currently, it is used on a larger scale as a lubricant. The size of MoS2 is a crucial parameter defining its properties. A preparation method that is easily scalable and cheap is currently being sought. A solution might be a wet chemical synthesis method carried out in an impinging jet reactor. The simple design of the reactor and the possibility of continuous operation make this method unique. In this study, the influence of the reactor was investigated using numerical simulations. The S-type reactor showed better mixing and more control over the working conditions than T-type. Therefore, the S-type reactor was chosen as better for nanoparticle synthesis. We also investigated the influence of the process conditions on the size of the precipitated MoS2 particles. The best operating conditions (i.e., Mo concentration of 0.2 mol/m3, reagent flow velocity of 20 mL/min, reaction temperature of 20 °C) were chosen to obtain the smallest particles (~200 µm). Additionally, two different reducing agents were also tested. The use of formic acid allowed obtaining smaller particle sizes but these were less stable than in the case of citric acid.