Abstract
Carbon nanofibers with high nitrogen doping level were prepared by electro-spinning and uniformly dispersed and crystalline NiO catalyst was loaded by chemical precipitation. The NiO nanofibers hybrid shows enhanced electrocatalytic activity and stability towards methanol oxidation in alkaline media.
•Highly nitrogen-doped carbon nanofibers (N-CNF) prepared by electro-spinning.•Preparation and characterization of NiO/N-CNF catalyst by chemical precipitation.•NiO/N-CNF catalyst shows enhanced electrocatalytic activity for methanol oxidation.
Uniform and highly doped nitrogen carbon nanofibers (N-CNFs) have been produced by electrospinning of solution mixture that contains polyacrylonitrile, polyaniline and graphene and followed by annealing at 1200°C. The NiO catalyst was loaded onto N-CNFs by chemical precipitation of Ni(OH)2 and treating at 400°C. The physicochemical characterizations show that the N-CNFs have an average diameter of 250nm with nitrogen-doping level of 17wt. % and BET surface area of 440m2g−1. The NiO catalyst with particle size of 7.0 to 8.0nm was uniformly loaded over the surface of the carbon nanofibers. The electrocatalytic activity of NiO/N-CNFs hybrid for methanol oxidation reaction in basic medium has been investigated by cyclic voltammetry and chronoamperometry techniques. The results show that the NiO/N-CNFs catalyst has superior specific and mass activities for methanol oxidation over the other nickel based catalysts. In addition negative shift in the methanol oxidation potential was observed which relies on the loading amount of NiO/N-CNFs catalyst. The highly doped nitrogen carbon nanofibers electrode based on polyacrylonitrile, polyaniline and graphene composite could be considered as a promising candidate to act as a catalyst support material.