Supercapacitor and oxygen evolution reaction performances based on rGO and Mn2V2O7 nanomaterials

Abstract

Manganese vanadate Mn2V2O7 (MVO), and reduced graphene oxide (rGO) have been synthesized for supercapacitors and electrocatalytic applications. The structure and electrochemical characterization studies were performed by several techniques, including XRD, SEM, TEM, XPS, BET, cyclic voltammetry (CV), Linear sweep voltammetry (LSV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The characterization tools of the investigated samples showed an amorphous structure for rGO and a monoclinic structure for MVO. The single electrodes of the investigated samples showed a specific capacitance of 120, 235, and 330 F/g for rGO, MVO, and rGO@MVO, respectively, in an electrolyte of 1M of LiClO4 in propylene carbonate solution. The electrochemical behavior of an asymmetric supercapacitor (ASC) of rGO@MVO//AC was studied under a potential window of 0–2 V, providing a high energy density of 66.6 Wh kg−1 at a power density of 19478 W kg−1. The ASC cell showed a specific capacitance of 112 F/g at a current density of 10 A/g and cycling stability with 86.6% capacitance retention over 8000 cycles. For oxygen evolution reaction, the rGO@Mn2V2O7 electrode showed a lower overpotential of 225 mV at a current density of 10 mA cm−2, with a Tafel slope of 54 mV dec−1, displaying a fast and effective reaction rate. These outcomes indicate that rGO@Mn2V2O7 can be used as hopeful electrode material for supercapacitor and water splitting applications.