Microwave-assisted synthesis of Mn3O4-Fe2O3/Fe3O4@rGO ternary hybrids and electrochemical performance for supercapacitor electrode

Abstract

Tailoring binary transition-metal oxide nanoparticles with two-dimensional novel carbon nanomaterials has become a desired way to increase their electrochemical performance for energy storage application. In this work, binary metal oxide (Mn3O4-Fe2O3/Fe3O4 nanoparticles) anchored reduced graphene oxide nanosheets (rGO NSs) have been successfully synthesized by a simple and low-cost microwave-assisted synthesis for supercapacitor (SCs) electrode applications. As characterized by scanning electron microscopy and transmission electron microscopy, Mn3O4-Fe2O3/Fe3O4 nanoparticles with size of <100 nm were effectively anchored on the surfaces or rGO NSs. The Mn3O4-Fe2O3/Fe3O4@rGO ternary hybrids was containing specific surface of ~322 m2/g. Cyclic voltammetry and galvanostatic charge/discharge measurements were adopted to investigate the electrochemical properties of Mn3O4-Fe2O3/Fe3O4 nanoparticles anchored rGO NSs (Mn3O4-Fe2O3/Fe3O4@rGO) ternary hybrids in 1.0 M KOH electrolyte solution. The Mn3O4-Fe2O3/Fe3O4@rGO ternary hybrids exhibited specific capacitance of 590.7 F/g at 5 mV/s and cyclic stability as capacitance retention of 64.5% after 1000 cycles at scan rate of 50 mV/s. Nearly rectangular shape of cyclic voltammetry curve revealed that electric double layer capacitance from conductive rGO NSs was dominated as compared to pseudocapacitance from binary metal oxide nanoparticles. The study presents a promising application of binary metal oxide/rGO hybrids as electrode materials for energy storage.