Optical and Structural Characterization of Molybdenum Disulphide Nanoflakes Prepared by Solvent-based Exfoliation

Two dimensional molybdenum disulfide nanoflakes; due to the emergence of new physical phenomena as well as promising practical applications such as field effect transistors, lithium ion batteries and gas sensors, have attracted considerable attention. However, finding new ways for large-scale production in a cost-effective way is one of the main bottlenecks in the development of these nanostructures. In this study, solvent-based exfoliation approach is introduced for the synthesis of two dimensional molybdenum disulfide nanoflakes by the use of ethanol/water mixture. Using this mixture offers distinct advantages including production of atomic scale nanoflakes, reduced residues of solvent used, high yield and high stability of suspension. Crystal phononic structure, energy gap and morphology of the synthesized nanoflakes have been investigated by using Raman scattering, absorption spectroscopy and atomic force microscopy, respectively. The optimum volume ratio for water and ethanol solvents was obtained equal to 55% and 45%, respectively. Optical characterization using absorption spectrum of the nanoflakes showed an energy gap of 1.7 eV for multilayer nanoflakes. The reported data reveals the production of two dimensional molybdenum disulfide nanoflakes.