Electrochemical properties of silver nanoparticle decorated on vertical graphene nanosheets

Abstract

Vertical Graphene Nanosheets (VGNs) can be described as graphite sheet nanostructures with edges that are composed of stacks of planar graphene sheets standing almost vertically on the substrate which has attracted much attention for energy storage application due to their unique properties such as large surface area, high electrical conductivity, and open 3D network structures. The present study reports VGNs synthesized on the nickel substrate under 5 mTorr gas pressure and CH4/Ar plasma in an Electron Cyclotron Resonance – Chemical Vapor Deposition (ECR-CVD) reactor. Further, a homogenous dispersion of Ag nanoparticles is coated over VGNs by the electrochemical deposition method. In this work, the electrochemical performance of VGNs/Ni and Ag-VGNs/Ni are investigated. The results for Ag-VGNs/Ni composites exhibit the higher specific capacitance of 318μF/cm2 compared to that of VGNs/Ni (70μF/cm2) at a scan rate of 20 mV/s. This enhanced capacitance can be a result of highly conductive 3D network of VGNs and also Ag nanoparticles conduction which can provide faster electron and ion transport. Scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy are also used to study the morphology and structure properties of the surfaces.