International Research Journal of Engineering and Technology (IRJET) Volume: 04 Issue: 02 | Feb -2017
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
SYNTHESIS AND CHARACTERIZATION OF MnO2/rGO NANOCOMPOSITE FOR SUPERCAPACITORS S.Yugambica1 Dr. Mrs. A.Clara Dhanemozhi2 and S.Iswariya 3 13M.Phil.,2 Associate
Professor
Department of Physics Jayaraj Annapackiam College for Women (Autonomous) Periyakulam - 625 605, Tamilnadu, India. ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract – In this paper we present a general approach for
the preparation of rGO/MnO2 nanocomposite. The Graphene oxide is produced by Modified Hummer’s method and it gets reduced to get rGO. The MnO2 nanoparticles were prepared by drop-feeding method and these MnO2 is mixed with rGO in order to form nanocomposite. Then the samples are characterized by UV, FTIR, XRD, SEM and Cyclic Voltammetry. XRD peaks reveal the particle size of the MnO 2 nanoparticles and rGO/MnO2. U-V Spectroscopy spectrum shows the absorbance for MnO2 nanoparticles. FTIR confirms the presence of respective functional groups. Then SEM images indicate structure for the prepared samples. From the CV curve specific capacitance is calculated & high capacitance value found to be 678 F/g value at san rate 5 mVs-1.
Key Words: rGO, Modified Hummer’s Method, Drop Feeding Method, Capacitance…
Cyclic
Voltammetry,
Specific
1.INTRODUCTION In response to the changing global landscape, energy has become a primary focus of the major world powers and scientific community. There has been great interest in developing and refining more efficient energy storage devices. Supercapacitors have attracted growing interest, due to their high power density, long cycle life, and fast charging rate, which is playing an important role in complimenting or even replacing batteries in many applications [1]. Supercapacitors also known as electrochemical capacitors have been a subject to many applications, research and development due to its high power density, environmental friendliness, long shelf life, long life cycle [2,3,4] and it bridges the energy gap between capacitors (high power output) and fuel cells/batteries (high energy storage) [5,6]. The carbon materials (activated carbon, carbon nanotubes, (CNT) and reduced graphene oxide (rGO)), transition metal oxides (ruthenium dioxide (RuO 2), © 2017, IRJET
|
Impact Factor value: 5.181
|
manganese dioxide (MnO2), nickel oxide (NiO), cobalt oxide (Co3O4) have been recognized as the most promising materials for supercapacitors. Among the transition metal oxides, MnO2 has attracted more attention as a pseudocapacitor electrode material and has been widely studied due to its high theoretical capacitance (1370 Fg−1), natural abundance, environmental compatibility and low cost. In order to improve the electrical conductivity of MnO2 electrodes, the incorporation of highly conductive secondary materials to form hybrid compounds is being investigated. The principal use for MnO2 is for dry-cell batteries, such as the alkaline battery and the zinc-carbon batteryMnO2 is also used as a pigment and as a precursor to other manganese compounds, such as KMnO4 and in Supercapacitors. Composite electrodes integrate carbonbased materials with either conducting polymer or metal oxide materials and incorporate both physical and chemical charge storage mechanisms together in a single electrode. Graphene oxide holds great potential to be coupled with MnO2, because it has high conductivity, good chemical stability, and a large surface area. MnO2/rGO composite electrode material is prepared by using appropriate methods on the purpose of using it in supercapacitor applications for energy storage.
2. EXPERIMENTAL PROCEDURE Materials used Graphite powder, Sodium Nitrate (NaNo3), Sulphuric acid (H2SO4), Hydrochloric acid (Hcl), Sodium Borohydride (NaBH4), Manganese Acetate, Ethanol, Ethylene Glycol, KMnO4 etc.,. Experimental steps were done in four parts, which are the preparation of the graphene Oxide by Modified Hummer’s Method, reduction of graphene Oxide by chemical method, preparation of MnO2 nanoparticles by drop-feeding method and the preparation of MnO2/rGO nanocomposite. ISO 9001:2008 Certified Journal
|
Page 486