ʟ-ascorbic acid-reduced graphite oxide as active material for supercapacitors

Abstract

Synthesis of reduced graphite oxide (rGO) via the chemical reduction of graphite oxide (GO) through a facile, environment friendly technique is discussed in this work. A non-toxic biocompound, ʟ-ascorbic acid, was the reducing agent and the rGO was used as active material for supercapacitor application. The reduction of GO yielded a two-dimensional structure of stacked layers, with an interlayer spacing comparable with that of graphite. The reduction was more prominent on the surface functionalities as inferred from XPS and elemental analysis. The symmetric supercapacitor, fabricated using neutral aqueous electrolyte, has an energy density of 19 Wh kg−1 and a power density of 1120 W kg−1. The material manifested a dominant capacitive behavior with prominent contribution from the surface processes. The variations in the contribution of surface and insertion processes with scan rates were analyzed. The appreciable capacitive retention of 93% after 1000 charge/discharge cycles and the considerable energy density values are corroborative of employing ʟ-ascorbic acid to synthesize rGO for supercapacitor applications.