Nitrogen doped carbon fibers were synthesized from polyvinyl alcohol (PVA), a water soluble precursor. The PVA fine fibers were first developed by centrifugally spinning an aqueous based solution using Forcespinning® technology. The precursor fibers were then exposed to sulfuric acid vapors to partially carbonize and stabilize the fibers for further heat treatment. For nitrogen doping, the fibers were exposed to two different heat treatment routes. One was under a nitrogen atmosphere at 850°C followed by exposure to ammonia gas at 500°C. The second route consisted of heating the treated fibers in pure ammonia gas only, up to 850°C. Both heating schemes resulted in carbon based fibers that showed evidence of nitrogen content as shown by energy-dispersive X-ray spectroscopy. The second route showed an effective doping of the carbon fiber with nitrogen atoms, measured by X-ray photoelectron spectroscopy, which indicated that the nitrogen atoms were fully incorporated into the carbon framework.
Cremar, Lee D., et al. "Nitrogen Doped Carbon Nanofibers Derived from Water-Soluble Precursors." Journal of Advances in Nanomaterials 2.4 (2017). https://dx.doi.org/10.22606/jan.2017.24002
Journal of Advances in Nanomaterials