Highly dispersed Fe3O4nanosheets on one-dimensional carbon nanofibers: Synthesis, formation mechanism, and electrochemical performance as supercapacitor electrode materials

Abstract

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.