Co-electrospun Pd-coated porous carbon nanofibers for hydrogen storage applications

Electrospinning produces sub-micron sized continuous fibers from polymer solutions or melt by electric force. Due to its versatility and cost-effectiveness, this method has been recently adopted for the fabrication of one-dimensional materials. Here, we fabricated polyacrylonitrile (PAN) polymer fibers from which uniform nanoporous carbon fibers with diameters of 100-200 nm were obtained after carbonization at 800 °C in Ar + H₂O. Water vapor was injected during carbonization to be utilized as a nanoscale pore former. Additionally, a direct coating method using palladium nanoparticles on the carbon fibers was developed. Palladium salt solution was electrosprayed during the electrospinning of the polymer fibers. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were used to confirm surface chemical composition and degree of carbonization. The specific surface area of the palladium coated carbon fibers was 815.6 m²/g. Reversible hydrogen adsorption capacity was determined to be 0.35 wt% at 298 K, 0.1 MPa.