Electron Beam Induced Synthesis of Ru-rGO and its Super Capacitive Behavior

Abstract

We report an in situ synthesis of ruthenium-reduced graphene oxide (Ru-rGO) using 6 MeV electron beam assisted radiolytic reduction method and its supercapacitive behavior. X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) explore Ru nanoparticles of size ~2 nm are decorated on rGO sheets. Raman spectroscopy shows I D/I G ratio increased and formation of bilayer rGO after electron beam irradiation. The defect density in Ru-rGO is increased due to the electron beam irradiation as compared to its counterpart GO. The Ru-rGO based supercapacitor exhibits specific capacitance (128.1 ± 5.59) F g−1 at 10 mV s−1 scan rate. The specific capacitance retention of Ru-rGO is up to 99.4% at 900 cycles while it increases to 130% at 5000 cycles. Discharge curve of the supercapacitor involves three current decay processes viz. activation polarization, ohmic polarization and concentration polarization. The highest energy density of (4.125 ± 0.19) W h kg−1 and power density of 1.44 kW kg−1 are achieved with Ru-rGO supercapacitor. This unique electron beam assisted techniques illustrates a promising method of the fabrication of high performance supercapacitor.