Hydrothermal growth of FeMoO4 nanosheets on electrospun carbon nanofibers as freestanding supercapacitor electrodes

Abstract

In this study, an electrospinning method was used to produce highly conductive freestanding carbon nanofibers (CNFs). The freestanding CNFs are compatible with hierarchical growth techniques, such as hydrothermal processes, for the nanostructure engineering of supercapacitor electrodes with enhanced electrochemically active sites. Therefore, the flower-like FeMoO4@CNF nanosheets were investigated to improve the electrochemical performance using aqueous and neutral electrolytes (Na2SO4 and K2SO4). The optimized FeMoO4@CNF electrode exhibits areal capacitances of 252 and 220 mF·cm−2 at a high current density of 2.5 mA·cm−2 with Na2SO4 and K2SO4 electrolytes, respectively. The wide potential window (1.6 V) of the symmetric supercapacitor delivered maximum energy densities of 22.4 and 19.6 μWh·cm−2 at a power density of 2 mW·cm−2 for Na2SO4 and K2SO4 electrolytes, respectively.