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

This work presents a comprehensive investigation into the phase engineering and interfacial reconstruction of 2D MoS2/graphene nanocomposites synthesized via hydrothermal treatment at 170-250 degrees C. A key innovation lies in the controlled modulation of the 1T/2H-MoS2 phase ratio, wherein low-temperature synthesis enables stabilization of the highly conductive 1T phase, while elevated temperatures promote a transition to the semiconducting 2H phase. Simultaneously, defect-laden graphene oxide is progressively restored to an sp(2)-hybridized network, facilitated by MoS2-mediated electron transfer and sulfur-assisted reduction. Raman spectroscopy reveals a significant I-D/I-G ratio decline (from approximate to 1.28 to approximate to 0.07) and increased lateral crystallite size (approximate to 15.0 to 260.6 nm), indicating enhanced graphitization. XPS and XRD investigation indicates a temperature-induced 1T-to-2H MoS2 phase transition, with Mo 3d (Mo 3d(5/2)/Mo 3d(3/2)) peaks shifting from approximate to 228.4/231.7 eV (1T phase) to approximate to 229.1/232.3 eV (2H phase), along with deoxygenation and reduced surface functionalization. HRTEM visualizes the emergence of coherent 2H-MoS2 nanodomains. Electrochemical analysis reveals a dramatic enhancement in conductivity (approximate to 2.1 x 10(-3) S m(-1)) and capacitance (approximate to 567.6 F cm(-2)), driven by optimized phase composition and interfacial synergy. These findings underscore the pivotal role of synthesis temperature in tailoring mixed-phase architectures and interfacial chemistry, offering a tunable platform for next-generation optoelectronic devices, energy storage, catalysis, and membrane technologies.