Interstitial Bimetallic Doping into Carbon Nanofibers By Electrospinning Technique: Electrochemical Supercapacitors

Abstract

Last decade, the supercapacitors (SCs) are well-recognized as promising energy storage devices because of their high-power density, long cyclic life, fast charge and discharge rates, and facile operational mechanism. Carbon materials such as active carbon, carbon nanotubes (CNTs), mesoporous carbon, graphene, etc. are highly suited electrode materials for supercapacitors owing to their high specific surface area, high electronic conductivity, and chemical stability against the corrosive electrolytes. In recent years, the mono or bimetallic transition metal doping into carbon materials has received immense attention because they significantly enhance the mechanical strength, electrochemical and physicochemical properties. Therefore, it is expected that the bimetallic doping into carbon nanofibers (CNFs) can be an innovative electrode for supercapacitors as they might improve the electrocatalytic and corrosive properties. In this work, the nickel (Ni) - copper (Cu) doping into the CNFs were prepared by a facile and controlled cost-effective electrospinning technique followed by stabilization of electrospun nanofibers. The prepared Ni-Cu doped CNFs were carbonized in the furnace for the partial decomposition of the polymer and irregular decomposition of the metallic acetate to complete NiCu in CNFs. By analyzing morphological characterizations, the NiCu was interstitially doped into CNFs. The surface analysis results revealed that NiCu doped CNFs exhibited a highly porous structure with a specific surface area of 244 m2/g and a large pore volume. The prepared NiCu doped CNFs were applied as the electrode and demonstrated exemplary electrochemical property with a reasonable specific capacitance of 337.5 F/g at 10 mV/s in aqueous 1M Na2SO4 electrolyte.