Hydrothermal Synthesis of Metal Sulfides (MS2; M = Mo and W) Nanostructures with their Structural and Optical Properties

Transition metal disulfides (MS2; M= Mo and W) nanostructures were successfully synthesized by a hydrothermal methodology based on the reaction between transition metal (Mo/W) and S sources at 240 °C for 24 hours. Detailed structural, morphological and optical analyses were performed using XRD, TGA/DSC, FESEM/EDX, HRTEM and UV-Vis spectroscopy. Gross structural investigations reveal that the crystalline nature of MS2 materials with flake-like and rod-like morphologies. MoS2 in 2D flake-like morphology with thickness of about 15 nm ( 2 nm) and WS2 in 1D rod-like morphology with width between 7-9 nm ( 0.5 nm) were achieved. The UV-Vis spectroscopy data elucidate two different optical band gaps 1.88 eV and 2.29 eV were achieved for MoS2 nanoflakes, and for WS2 nanorods it was 1.84 eV. The simple and cost-effective synthesis approach with detailed microstructure analyses and optical properties indicate a great potential of nanostructured MoS2 and WS2 as a vital component in new-generation semiconductor and optoelectronics devices.