Silver Nanoparticle Decorated on Reduced Graphene Oxide-Wrapped Manganese Oxide Nanorods as Electrode Materials for High-Performance Electrochemical Devices

Abstract

In this work, silver nanoparticles decorated on reduced graphene oxide (rGO) wrapped manganese oxide nanorods (Ag-rGO@MnO2) were synthesized for an active electrode material. MnO2 nanorods were synthesized via a hydrothermal route, and their coating with GO and subsequent reduction at a higher temperature resulted in rGO@MnO2. A further addition of Ag on rGO@MnO2 was performed by dispersing rGO@MnO2 in AgNO3 solution and its subsequent reduction by NaBH4. X-ray diffraction (XRD) analysis showed peaks corresponding to MnO2 and Ag, and the absence of a peak at 2θ = 26° confirmed a few layered coatings of rGO and the absence of any graphitic impurities. Morphological analysis showed Ag nanoparticles anchored on rGO coated MnO2 nanorods. Apart from this, all other characterization techniques also confirmed the successful fabrication of Ag-rGO@MnO2. The electrochemical performance examined by cyclic voltammetry and the galvanic charge–discharge technique showed that Ag-rGO@MnO2 has a superior capacitive value (675 Fg−1) as compared to the specific capacitance value of rGO@MnO2 (306.25 Fg−1) and MnO2 (293.75 Fg−1). Furthermore, the electrode based on Ag-rGO@MnO2 nanocomposite showed an excellent capacity retention of 95% after 3000 cycles. The above results showed that Ag-rGO@MnO2 nanocomposites can be considered an active electrode material for future applications in electrochemical devices.