Electrochemical performance of ternary RGO/β-Ni(OH)2/CeO2 composite in addition with different metal oxides for supercapacitor application

Sreenivasa Kumar Godlaveeti, Hussen Maseed, Somala Adinarayana Reddy and Ramamanohar Reddy Nagireddy

Abstract

Herein, we demonstrate a facile ternary nanocomposite synthesis of the RGO/β-Ni(OH)₂/CeO₂ hydrothermal route followed by a solid-state method at room temperature. Firstly, RGO, β-Ni(OH)₂ and CeO₂ were taken with different weight ratios in a mortar pestle and prepared by solid-state method to obtain ternary RGO/β-Ni(OH)₂/CeO₂ nanocomposite. The as-prepared powder samples and fabricated electrodes for supercapacitors were systematically investigated. Further, a very low quantity of as-prepared bare TiO₂ nanorods (NRs), SnO₂ nanparticles (NPs) and MnO₂ NRs was added to the above-obtained ternary composite to prepare quaternary nanocomposite. The as-prepared material crystalline structure, morphological and elemental analyses were examined by using different characterisation techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive x-ray spectroscopy (EDX). The electrochemical properties of as-characterised ternary and quaternary composites were examined by using the cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The obtained results have shown that prepared ternary composite in addition with MnO₂ NRs was endowed with superior specific capacitance (1250 F.g⁻¹) at current density 0.5 A.g⁻¹ in 3 M KOH aqueous electrolyte solution as compared with other metal oxides of SnO₂ NPs and TiO₂ NRs. After 3000 cycles ternary nanocomposite in addition with MnO₂ NRs retained 78.46%, showed better cyclic stability. Based on these results it can be concluded that the novel ternary/quaternary composite of RGO/β-Ni(OH)₂/CeO₂ can serve as promising electrode material in next-generation supercapacitors.