High Surface\nArea Microporous Activated Carbon from\nCorn Fiber Using Graphene Oxide-Assisted Hydrothermal Carbonization

Abstract

This study investigated a novel process that explored\nthe use of\ngraphene oxide (GO) as a catalyst in the hydrothermal carbonization\n(HTC) process of low-value, high moisture-containing corn fiber (CF)\nto analyze the morphology, surface area, and porosity characteristics\nof activated carbon (AC) derived from GO-assisted hydrochar. The SEM\nresults showed significant alteration to the hydrochar morphology\nrevealing carbon spheres with flakes or platelet-like structures when\nGO was added to the process, which led to increased carbonization\nand promoted the hydrochar surface area. The surface areas of the\nACs produced from the hydrochars were further increased, and a well-developed\nporous structure was produced with significant micropore volume. The\nhighest surface area of 2549.1 m²/g obtained for the AC\nderived from the hydrochar with the highest GO ratio. Despite the\nabsence of a strong trend between the GO ratio and AC surface area,\nthe SEM analysis and pore size results revealed that the ACs derived\nfrom the GO-assisted hydrochars had more intact structures and smaller\nmicropores with interconnected pore channels which would be very favorable\nfor hydrogen storage capacity. The nitrogen content in the ACs was\nalso found to be comparable or higher than carbons from other studies\nusing nitrogen doping steps and was detected in surface functional\ngroups through FT-IR and XPS analysis. Overall, the developed process\nprovides valuable insight into the influence of GO for tailoring porous\ncarbon materials to enhance surface area and pore structure in low-cost\nand effective bio-based adsorbents, offering opportunities for emerging\napplications while promoting circular economy principles.