Effective carbon dioxide stabilization of nanofibers electrospun from raw coal tar and polyacrylonitrile

Abstract Non-fuel utilizations of coal for sustainable carbon materials production is certainly beneficial to the abatement of anthropogenic carbon dioxide emissions. Also, the technological uses of carbon dioxide are emergent to the earlier realization of the Paris Climate Agreement. This research was innovatively designed to produce carbon nanofibers from Wyoming Powder-River-Basin coal-derived supercritical extraction liquid (referred to raw coal tar) along with predetermined percentages of polyacrylonitrile by electrospinning, fiber stabilization with carbon dioxide, and subsequent carbonization treatment. The effects of raw coal tar additives to polyacrylonitrile nanofibers regarding the structural, textural and surface properties were investigated. Attenuated total reflection and diffuse reflectance infrared Fourier transform analyses reveal the difference in the dynamic evolution pathways of surface functional groups during the state-of-the-art oxygen-based and the new carbon dioxide-based fiber stabilization processes. In terms of mechanical properties, raw coal tar modifications give significant rise to the tensile strength of annealed polyacrylonitrile nanofibers, regardless of oxidative stabilization options. Additionally, the synergy of raw coal tar containing (30 wt. %) polymeric precursor and carbon dioxide stabilization produces carbon nanofibers with a superior area-normalized electric double-layer capacitance of 1408.9 μF/cm2, which is approximately 4 times higher than the oxygen-stabilized pure polyacrylonitrile-derived ones.