Moringa oleifera Leaf Extract Mediated Reduced Graphene Oxide/α-Ni(OH)2 Nanocomposite for Asymmetric Supercapacitors

• Published in: Brazilian journal of physics Vol. 49; no. 3; pp. 348 - 359
• Main Authors: Reddy, B. Joji, Vickraman, P., Justin, A. Simon
• Format: Journal Article
• Language: English
• Published: New York Springer US 15.06.2019; Springer Nature B.V
• Subjects: Electrochemical analysis; Flux density; General and Applied Physics; Graphene; Leaves; Nanocomposites; Nickel compounds; Physics; Physics and Astronomy; Supercapacitors; X ray photoelectron spectroscopy; Cyclic stability; Redox couple; Graphene composite; Ni(OH)
• ISSN: 0103-9733; 1678-4448
• DOI: 10.1007/s13538-019-00640-1

An attempt has been made in preparing graphene composite matrix with Ni(OH) 2 in a green route via Moringa oleifera plant leaf extract in an ordinary co-precipitation method for supercapacitor applications. The as-prepared graphene and its composites with various molar ratios of Ni(OH) 2 are investigated by XRD, UV, Raman, XPS, SEM, and TEM analyses which have confirmed the conversion of graphene oxide into reduced graphene oxide and its complexation with Ni(OH) 2 . Electrochemical activity of the samples is examined by using CV, GCD, and EIS techniques in 2 M KOH electrolyte solution. The leaf extract-reduced graphene oxide has shown pure EDLC behavior, and its composites with Ni(OH) 2 have contributed good redox couple leading to enhanced electrochemical performance of 350.7 F g −1 at 0.5 A g −1 . In the two-electrode set-up for asymmetric supercapacitor design, rGO//rGO-Ni(OH) 2 has performed good reversible cyclabilty with the energy density of 34.2 Wh kg −1 and power density of 507.5 W kg −1 at 2 A g −1 . The device shows good cyclic stability for 6000 successive charge/discharge cycles, and therefore, the green option can be one of the best alternatives for advancing supercapacitor technology.