Multi-functional Coal-Derived Graphene Films

G.G. Botte
Ohio University,
United States

Keywords: graphene, nanotechnology, electronic conductivity

Summary:

Coal-Derived Graphene films have been produced via an innovative two-step process: coal electrolysis and chemical vapor deposition (CVD). Coal electrolysis is used to activate the surface of the coal particles and build saturated carbon films/compounds. These films are subsequently converted to few-layer graphene films via coal pyrolysis in hydrogen (a by-product of coal electrolysis in the first step). These films are currently deposited on copper, but can be optimized for and deposited on other substrates of choice. These combined techniques (electrolysis and CVD) incorporate inexpensive raw material usage with high purity graphene (thermal-based as opposed to solvent-based technique) and scalability (roll-to-roll production). In summary, Coal-Derived Graphene provides a foundation for overcoming market impediments for graphene-enabled devices and systems. The graphene films produced have demonstrated dynamic properties such as high transparency and low disorder as well as improved catalytic properties in separate electrochemical applications (electrolyzers and battery). The films produced can be further modified for use in polymer composites and conductive coatings via pre-CVD substrate design or post-CVD processing for preferred graphene morphology and characteristics. Advances since TechConnect 2015 include: Increased purity due to de-coupling of coal pyrolysis from chemical vapor deposition and conductivity delineation. Graphene’s properties are well known and could potentially be used in both stand-alone technologies e.g. electronics and display applications as well as in composites for mechanical reinforcement and improved conductivity. Coal-Derived Graphene as a technology is a promising approach for significant cost reduction through a combination of cheap raw material and substrate use optimization. In addition, Coal-Derived Graphene yields high quality graphene film with high transparency, minimal defects and high electronic conductivity based on in-house measurements. Samples are available for testing by potential industrial partners.