Ultrasound assisted synthesis of Mn3O4 nanoparticles anchored graphene nanosheets for supercapacitor applications

Abstract Mn 3 O 4 nanoparticles anchored graphene nanosheets (MG) have been successfully synthesized by a simple ultrasound assisted synthesis at room temperature without the use of any templates or surfactants for supercapacitor applications. Upon ultrasound assisted synthesis, the formation of Mn 3 O 4 nanoparticles and the graphene oxide reduction occurs simultaneously. The crystalline structure of thus prepared MG nanocomposite have been characterized by the powder X-ray diffraction (XRD) analysis. Thermo Gravimetric Analysis (TGA) is used to determine the mass content of graphene (17 wt%) in the MG nanocomposite. Transmission electron microscopy (TEM) and Atomic force microscopy (AFM) studies shows that the Mn 3 O 4 nanoparticles (4–8 nm) were uniformly anchored on the surface of graphene nanosheets. The electrochemical properties of the MG nanocomposite were investigated by employing cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The capacitive properties of MG nanocomposite studied in the presence of 1 M Na 2 SO 4 exhibited high specific capacitance of 312 F g −1 which was approximately three times greater than that of pristine Mn 3 O 4 (113 F g −1 ) at the same current density of 0.5 mA cm −2 in the potential range from -0.1 to +0.9 V. About 76% of the initial capacitance was retained even after 1000 cycles establishes the fact that MG nanocomposite exhibited good electrochemical stability and capacitance retention capability also.