Comparative Evaluation of Coal-Derived and Commercial Graphene Oxides in Concrete Strength Performance

Graphene oxide (GO) enhances concrete performance through its high surface area, strong mechanical properties, oxygen-rich functional groups, and ability to improve hydration, durability, and microstructure. While the modified Hummers’ method is commonly used for GO synthesis, its reliance on strong acids and oxidizers makes it costly and less suitable for low-rise construction. We developed a simple one-pot method using nitric acid derived from Powder River Basin coal in Wyoming, USA. A nitric-acid-based synthesis offers a safer, cost-effective, and environmentally friendly alternative to the traditional Hummers’ method, enabling scalable production of oxygen-rich GO suitable for cement applications. Our coal-derived GO was compared with commercially available graphene-derived GO (CGO) and other coal-derived derivatives, including reduced GO (CDrGO), base-treated GO (CDBGO), and flash-pyrolyzed GO (CDFGO), all tested at a concentration of 0.05% by weight of cement replacement. Experimental results showed that CDGO and CDrGO significantly enhanced compressive strength (18 to 28%) and elasticity (up to 36%) while maintaining Poisson’s ratio of 0.15. Isothermal calorimetry confirmed accelerated early hydration and denser concrete formation. These findings support CDGO and its variants as cost-effective alternatives to CGO, enabling the sustainable use of Wyoming coal and reducing cement-related environmental impact.