Tin oxide (SnO 2) nanoparticles/electrospun carbon nanofibers (CNFs) heterostructures: Controlled fabrication and high capacitive behavior

Abstract

Tin oxide (SnO 2)/carbon nanofibers (CNFs) heterostructures were fabricated by combining the versatility of the electrospinning technique and template-free solvent–thermal process. The results revealed that the SnO 2 nanostructures were successfully grown on the primary electrospun carbon nanofibers substrates. And, the coverage density of SnO 2 nanoparticles coating on the surface of the CNFs could be controlled by simply adjusting the mass ratio of CNFs to SnCl 4·5H 2O in the precursor during the solvent–thermal process for the fabrication of SnO 2/CNFs heterostructures. The electrochemical performances of the SnO 2/CNFs heterostructures as the electrode materials for supercapacitors were evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurement in 1 M H 2SO 4 solution. At different scan rates, all the samples with different coverage densities of SnO 2 showed excellent capacitance behavior. And, the sample CS2 (the mass ratio of CNFs to SnCl 4·5H 2O reached 1:7) exhibited a maximum specific capacitance of 187 F/g at a scan rate of 20 mV/s. Moreover, after 1000 cycles, the specific capacitance retention of this sample was over 95%. The high capacitive behavior could be ascribed to the low resistance of SnO 2/CNFs heterostructures and rapid transport of the electrolyte ions from bulk solution to the surface of SnO 2.