Highly ordered 1D NiCo2O4 nanorods on graphene: An efficient dualfunctional hybrid materials for electrochemical energy conversion and storage applications

Abstract

One dimensional porous binary metal oxides exert much more attention for electrochemical energy conversion and storage applications. Herein, we report a simple process for the synthesis of one dimensional mesoporous rod-like NiCo2O4 structure (NCO NRs) grown on reduced graphene oxide sheets (RG/NCO NCs). This noble metal free RG/NCO NCs composite manifested as the dual-functional electrode material for the electrochemical oxygen evolution reaction (OER) and supercapacitor applications. The RG/NCO NCs shows significant OER performance with prosperous reaction kinetics with a smaller Tafel slope of 35 mV dec(-1). It requires only 313 mV overpotential to deliver 10 mA cm(-2) current density, showing superior OER activity compared to some of the state-of-art electrocatalysts under similar electrochemical conditions. Moreover, the RG/NCO NCs showed enhanced energy storage efficacy in terms of higher specific capacitance (1315 F g(-1)), long-term operational durability, higher specific energy and power output. The porous structure, higher specific surface area and better electrochemical conductivity of the RG/NCO NCs make it a suitable material for both the energy conversion and storage application. Additionally, to validate the supercapacitor performance, a prototype device in coin cell configuration has been designed and successfully tested to power a LED. (C) 2018 Elsevier Ltd. All rights reserved.