Preparation and electrochemical properties of sodium-reduced graphene oxide

Graphite oxide reduction is probably one of the best technique used to obtain large quantities of few-layer graphene. We developed a new method to produce reduced graphene oxide by using sodium metal as a reducing agent with subsequent dehydration in concentrated sulfuric acid. The resulting product was characterized using various analytical techniques with respect to the oxygen content and species of the residual oxygen-containing groups. The reduced graphene oxide prepared by this method was electrochemically tested as electrode in supercapacitors using two-electrode symmetric system and aqueous electrolyte. The product exhibits improved capacitance during cyclic voltammetry measurements. In comparison to parent graphite oxide specific capacity increased from 0.88 to 28 F/g after 10 cycles at scan rate 20 mV/s and dropped to 19.44 F/g after 100 cycles while at scan rate 5 mV/s specific capacity 46.41 F/g was recorded after first cycle and 39.90 F/g after 50 cycles.