Preparation of N‐doped graphene‐based electrode via electrochemical method and its application in vanadium redox flow battery

Summary An N‐doped graphene electrode has been prepared by cyclic voltammetric method in 5.0 M of HNO3 solution on a graphite‐based electrode at room temperature. The modification of the electrode surface with different types of N‐containing groups, such as nitro groups, pyrrolic N, and pyridinic N, has been controlled by changing the scanned potential ranges. The formation of an N‐doped graphene electrode has been confirmed by scanning electron microscopic, atomic force microscopic, X‐ray photoelectron, and Raman spectroscopic methods. The prepared N‐doped graphene‐modified electrodes have been used in positive electrolyte of a vanadium‐based redox flow battery. As positive electrodes, the electrochemically modified electrodes prepared in 5.0 M of HNO3 solution −1.0 to (+1.9) and −0.7 to (+1.9) V had more than 140 and 120 mA/cm2 anodic and cathodic peak currents, respectively, in vanadium redox battery. This fast, low‐cost, and environmentally friendly method can be used in many application areas, such as optical devices, (bio)sensors, energy storage materials, and electronic devices.