Methane pyrolysis is a widely used technique for producing hydrogen and valuable carbon materials. Among these materials are carbon films, which have a diverse range of properties that make them useful for various applications. This study focuses on synthesizing a new type of carbon film through a microwave-driven methane pyrolysis process. The resulting metallic-like carbon film deposits on a polished quartz substrate and detaches as it thickens. We conducted a thorough characterization of the film's properties, using different techniques to study its surface morphology and structural features. Our findings show that the carbon film has a smooth surface texture and a semi-graphitic internal structure, with 78% of the carbon atoms exhibiting sp2 bonding as revealed by X-ray photoelectron spectroscopy. X-ray diffraction analysis further confirms the presence of microcrystalline carbon fragments within the film. Additionally, conductivity measurements using a conductive-atomic force microscope demonstrate the carbon film's remarkable electrical conductivity, comparable to that of gold and silver metals. The electrochemical measurements indicate that the carbon film's high conductivity and free-standing nature make it a promising candidate for use as a direct active material in sodium-ion batteries. This is because the film does not require binders or conductive agents, which can improve battery performance.
