Highly dispersed Fe3O4 nanosheets on one-dimensional carbon nanofibers: Synthesis, formation mechanism, and electrochemical performance as supercapacitor electrode materials

Highly dispersed Fe3O4 nanosheets on one-dimensional (1D) carbon nanofibers (CNFs) were firstly fabricated by combining the versatility of the electrospinning technique and solvent-thermal process. The electrochemical performances of the Fe3O4/CNFs nanocomposites as the electrode materials for supercapacitors were evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurement in 1 M Na2SO3 electrolyte. At different scan rates, the sample showed excellent capacitance behavior. The high capacitive behavior could be ascribed to the high electrical conductivity and the one-dimensional properties of the CNFs in Fe3O4/CNFs nanocomposites, which could decrease the charge transfer resistance of the Fe3O4. At the same time, the high specific surface area and high level exposure of the Fe3O4 nanosheets on the surface of the CNFs increased the electrochemical utilization of Fe3O4. Moreover, in comparison to the pure Fe3O4 (83 F g−1), the as-prepared Fe3O4/CNFs nanocomposites electrode exhibited a higher specific capacitance (135 F g−1). Meanwhile, the supercapacitor devices of the Fe3O4/CNFs nanocomposites exhibited excellent long cycle life along with 91% specific capacitance retained after 1000 cycle tests. Finally, a possible mechanism for the formation of the Fe3O4 nanosheets on the surface of CNFs was suggested.