The effect of surface tension of the liquid medium on the efficiency of the fabrication process of disulfide molybdenum nanoshells using an ultrasonic probe

Ultrasonication in liquids is one of the most important approaches to exfoliate 2D materials. Here we described some experiments based on Liquid Phase Exfoliation of Molybdenum Disulfide (MoS2) powder in the water-ethanol solution without any additives. It is reported that MoS2 as a prototype 2D Transition Metal Dichalcogenide, has a bandgap that increases with decreasing layer thickness. There are some factors that affect the average band gap energy value (and the thickness of the exfoliated flakes). In this study, 2D nanoflakes of Molybdenum Disulfide (MoS2) were produced using an ultrasonic probe in various solutions. Because of the key role of surface tension in the exfoliation process, and also to reduce the negative effects of chemical residues on the environment, we used a binary solution consisting of water and ethanol with the ratio determining based on the Connors-Wright equation. Our findings from UV-Visible spectroscopy show that the best efficiency, i.e. the minimum thickness of MoS2 nanoflakes, is obtained for the solution with the mentioned solution. The FESEM and TEM images, and the XRD pattern confirmed that we obtained the few-layers of MoS2.