Hydrothermal Phase Engineering of 1T/2H MoS2/Graphene Nanocomposites for Enhanced Electronic, Catalytic, and Electrochemical Performance

This study examines how hydrothermal temperature controls the phase composition of two-dimensional MoS2/graphene nanocomposites. Samples were synthesised between 170 and 250 °C and characterised with Raman spectroscopy, XPS, XRD, HRTEM and electrochemical measurements. Lower temperatures stabilise the conductive 1T phase, while higher temperatures drive a gradual conversion to the semiconducting 2H phase and, at the same time, reduce and restore the graphene oxide. The Raman D/G intensity ratio falls from about 1.28 to about 0.07 and the lateral crystallite size grows from about 15 nm to about 260 nm, indicating stronger graphitisation. The results point to synthesis temperature as a design parameter for balancing the electrical conductivity, catalytic activity and electrochemical behaviour of the material.