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.