Solution-processed multifunctional graphene and Graphene/MoS₂ heterostructure films

We present a scalable solution-processing method for fabricating high-quality graphene and graphene/1T-MoS₂ heterostructure films. The process begins with the synthesis of potassium-intercalated graphite (KC₈), which is exfoliated in tetrahydrofuran (THF) to produce stable dispersions of negatively charged (electron rich) graphene sheets. The graphene is subsequently transferred to water, forming a surfactant-free aqueous dispersion suitable for creating homogenous graphene films via vacuum filtration and stamping. Additionally, graphene is combined with 1T-MoS₂ nanosheets to fabricate graphene/1T-MoS₂ bulk heterostructure films. Comprehensive characterization, including X-ray diffraction (XRD), absorption spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photon emission spectroscopy (XPS), reveals that the heterostructure films exhibit enhanced optical and electronic properties, including improved light absorption, which could lead to novel photo-responsive devices. Raman spectroscopy shows significant changes in the graphene's structural and electronic properties upon interaction with MoS₂, indicating strong interlayer coupling and potential charge transfer between the layered components. The graphene films demonstrate highly sensitive detection of dopamine (DA), while the graphene/1T-MoS₂ bulk heterostructure films exhibit capacitance values up to 38.3 Fg⁻¹ at 5 mV/s in non-aqueous electrolytes. These results highlight the potential of these films for advanced applications in molecular sensing and energy storage.