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 them, molybdenum disulfide (MoS2) nanosheets possess remarkable optical, electronic, and chemical properties. This study employed a cost-effective hydrothermal method to successfully 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. XRD analysis indicates the MoS2 nanosheets exhibit a hexagonal crystal structure. The formation of thin MoS2 nanosheets was observed through SEM images. 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.