Graphene-gold nanoparticle-based nanocomposites as an electrode material in supercapacitors

We prepared graphene-gold nanocomposites chemically from graphene oxide obtained from graphite oxide. We also synthesized the same nanocomposites using high-energy gamma radiation. The as-synthesized nanocomposites were characterized by UV-visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction study. The nanocomposites were used as the electrode material in a low cost and environmental-friendly energy storage device supercapacitor. It exhibited stable specific capacitance values of 100 and 500 F/g for the nanocomposites electrodes synthesized chemically and using gamma radiation, which remained constant over potential scan rate of 5-500 mV/s. The fabricated electrode in the supercapacitor device exhibited excellent long cycle life along with retention of ~90 % specific capacitance value after 600 cycle tests. (author)