Experimental Investigation of Molybdenum Disulfide Purification Through Vacuum Distillation

The properties and applications of molybdenum disulfide (MoS 2 ) are significantly dependent on its purity. Physical purification is proposed for separating impurities from MoS 2 . Meanwhile, the feasibility of separation of impurities was analyzed by thermodynamic calculations. The effects of the temperature and heating duration on the volatilization of impurities were studied experimentally. The purity of MoS 2 was notably improved by vacuum distillation at optimized processing conditions. The phase of the volatiles and the microstructural change of the residues were investigated and characterized by X-ray diffraction analysis, scanning electron microscopy, electron probe microanalysis, Raman spectroscopy, and atomic force microscopy. Graphical Abstract Vacuum distillation is a scalable one-step approach to separate impurities from molybdenum disulfide. The purity of the residual MoS 2 significantly depends on the distillation temperature and duration. Tiny amounts of impurities were collected and analyzed by phase determination. The transformation to multilayer stacks is attributed to the high temperature used during vacuum distillation.