Hierarchical carbon composite nanofibrous electrode material for high-performance aqueous supercapacitors

In this research, a hierarchical carbon composite nanomaterial ECNFs/PtNPs, which is composed of electrospun carbon nanofibers (ECNFs) with both individual and agglomerate of Pt nanoparticles (PtNPs) homogeneously dispersed all over the ECNF surface, was prepared by successive electrospinning, carbonization, and controlled growth of the PtNPs. Morphology and structure of ECNFs and ECNFs/PtNPs with a variety of amount of PtNPs were characterized by scanning electron microscope, x-ray diffraction and BET surface area analysis. The ECNFs/PtNPs was evaluated as electrode material for supercapacitor with aqueous electrolyte. The results indicated that Pt nanoparticles on surface of ECNFs drastically increased specific capacitance as well as potential energy density of the electrode material by 50 times to 226 F g−1 and 20 W h kg−1, respectively, at 0.14 g/cm2 Pt loading with 6M KOH aqueous electrolyte. This is ascribed to the highly catalytic activity of PtNPs in the hierarchical nanostructure for oxygen reduction reaction in alkali aqueous electrolyte, which leads to significant pseudocapacitance. This research discloses a novel nanofibrous electrode material from electrospinning with great potential for designing high-performance supercapacitors using aqueous electrolyte.