Bridge effect of silver nanoparticles on electrochemical performance of graphite nanofiber/polyaniline for supercapacitor

In this work, silver (Ag) nanoparticles were deposited onto graphite nanofibers (GNFs) by chemical reduction while polyaniline-coated Ag-GNFs (Ag-GNFs/PANI) were prepared by in situ polymerization. The effect of the Ag nanoparticles intercalated in composite interface on the electrochemical performances, such as CV curve, charge-discharge behaviors, and specific capacitance of the GNFs/PANI was investigated. It was found that nano-sized Ag particles could be uniformly deposited onto the GNFs and that Ag-GNFs were successfully coated by PANI via in situ polymerization. According to the charge-discharge curves, the highest specific capacitance (212 F/g) of the Ag-GNFs/PANI was obtained at a scan rate of 0.1 A/g, as compared to 153 F/g for GNFs/PANI and 80 F/g for PANI. This indicated that the Ag nanoparticles that were deposited onto the GNFs led to a bridge effect between GNFs and PANI to improve the charge transfer, which resulted in the enhanced electrochemical performances of the composites due to a synergistic effect.