Electrophoretically-deposited nano-Fe3O4@carbon 3D structure on carbon fiber as high-performance supercapacitors

Abstract

Structural and electrochemical behaviors of electrophortically-deposited Fe3O4 and Fe3O4@C nanoparticles on carbon fiber (CF) were investigated. The nanoparticles were synthesized via a green-assisted hydrothermal route. The as-prepared samples were characterized by x-ray diffraction, transmission and scanning electron microscopies, Fourier transform infrared and UV–visible spectroscopies as well as by a vibration sample magnetometer. Surprisingly, the saturation magnetization (Ms) of the Fe3O4@C (~ 26.99 emu/g) was about 20% higher than that of Fe3O4 nanoparticles. A rather rectangular CV curve for both the elecrophortically-deposited Fe3O4 and Fe3O4@C on CF indicated the double-layer supercapacitor behavior of the samples. The synergistic effects of double shells improved the electrochemical behavior of Fe3O4@CF. The Fe3O4@C@CF composite exhibited a higher specific capacitance of ~ 412 F g−1 at scan rate of 0.05 V/s compared to the Fe3O4@CF with a value of ~ 193 F g−1. The superb electrochemical properties of Fe3O4@C@CF confirm their potential for applications as supercapacitors in the energy storage field.