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W e present a scalable solution-processing method for fabricating high-quality graphene and graphene/1T-MoS 2 heterostructure films. The process begins with the synthesis of potassium-intercalated graphite (KC 8 ), 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-MoS 2 nanosheets to fabricate graphene/1T-MoS 2 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 a nd electronic properties upon interaction with MoS 2 , indicating strong interlayer coupling and potential charge transfer between the layered components. The g raphene films demonstrate highly sensitive detection of dopamine (DA), while the graphene/1T-MoS 2 b ulk heterostructure films exhibit capacitance values up to 3 8.3 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. 

Abstract The field of photovoltaics is revolutionized in recent years by the development of two–dimensional (2D) type‐II heterostructures. These heterostructures are made up of two different materials with different electronic properties, which allows for the capture of a broader spectrum of solar energy than traditional photovoltaic devices. In this study, the potential of vanadium (V)‐doped WS₂is investigated, hereafter labeled V‐WS₂, in combination with air‐stable Bi₂O₂Se for use in high‐performance photovoltaic devices. Various techniques are used to confirm the charge transfer of these heterostructures, including photoluminescence (PL) and Raman spectroscopy, along with Kelvin probe force microscopy (KPFM). The results show that the PL is quenched by 40%, 95%, and 97% for WS₂/Bi₂O₂Se, 0.4 at.% V‐WS₂/Bi₂O₂Se, and 2 at.% V‐WS₂/Bi₂O₂Se, respectively, indicating a superior charge transfer in V‐WS₂/Bi₂O₂Se compared to pristine WS₂/Bi₂O₂Se. The exciton binding energies for WS₂/Bi₂O₂Se, 0.4 at.% V‐WS₂/Bi₂O₂Se and 2 at.% V‐WS₂/Bi₂O₂Se heterostructures are estimated to be ≈130, 100, and 80 meV, respectively, which is much lower than that for monolayer WS₂. These findings confirm that by incorporating V‐doped WS₂, charge transfer in WS₂/Bi₂O₂Se heterostructures can be tuned, providing a novel light‐harvesting technique for the development of the next generation of photovoltaic devices based on V‐doped transition metal dichalcogenides (TMDCs)/Bi₂O₂Se.