Facile Room Temperature Synthesis of Reduced Graphene Oxide as Efficient Metal-Free Electrocatalyst for Oxygen Reduction Reaction

Abstract

A continuous global demand for energy resources poses serious threats to the human race in forms of pollution that stimulates many natural hazards. To overcome such problems, fuel cell technology seems to be a viable solution. However, it remains a challenge to develop highly efficient metal-free electrocatalysts for oxygen reduction reaction (ORR) to achieve optimal performance for the fuel cells. Herein, we demonstrate a facile room temperature synthesis of reduced graphene oxide (RGO) via chemical reduction of graphene oxide (GO) using sodium iodide (NaI) and hydrochloric acid (HCl). As-synthesized GO and RGO were employed as an efficient electrocatalyst for the ORR in 0.1 M KOH. The RGO shows higher ORR activity compared to GO due to its higher surface area and low charge transfer resistance. Thus as-synthesized RGO is found to be a viable metal-free electrocatalyst with higher current density, larger half-wave potential, and long-term operation stability for ORR via a four-electron pathway in alkaline media. The high performance of cost-effective RGO-based ORR electrodes is suitable to function as an alternative to platinum-based materials for energy conversion device applications.