Morphological and Optical Characterization of Hydrothermally-Synthesized Two-Dimensional MoS2 Nanosheets

Abstract

Transition metal dichalcogenides (TMDs) are extensively utilized in optoelectronics, sensors, and battery storage due to their versatile properties. Among the TMDs, Molybdenum disulfide (MoS2) nanosheets possess remarkable optical, electronic, and chemical properties. This study employed a cost-effective hydrothermal method to synthesize high-quality 2D MoS2 nanosheets. Different characterization techniques such as XRD, SEM, EDS, FTIR, Raman, UV–vis, and photoluminescence (PL) spectroscopy were utilized to evaluate the structural, morphological, chemical, and optical characteristics of the nanosheets. The XRD analysis revealed that the MoS2 nanosheets have a hexagonal crystal structure, with an average crystallite size of 27.76 nm. Furthermore, SEM images confirmed the formation of thin MoS2 nanosheets, with an estimated thickness ranging from 20–30 nm. The growth mechanism of the formation of MoS2 is discussed in detail. Different functional groups present in the material were analyzed using FTIR spectra. The difference in vibration modes analysed by Raman spectroscopy indicated the presence of layered nanosheets. The optical bandgap (2.20 eV) of the material was determined by analyzing its UV–vis spectroscopy data using the Tauc plot. PL analysis indicates a direct transition between the upper valence and lower conduction bands, suggesting that the nanosheets were synthesized with high quality. These findings have opened new possibilities for the use of MoS2 nanosheets in various applications such as optoelectronics and sensing devices.