Porous Hybrid Network of Graphene and Metal Oxide Nanosheets as Useful Matrix for Improving the Electrode Performance of Layered Double Hydroxides

Abstract

Mesoporous hybrid network of reduced graphene oxide (rG-O) and layered MnO2 nanosheets could act as an efficient immobilization matrix for improving the electrochemical activity of layered double hydroxide (LDH). The control of MnO2/rG-O ratio is crucial in optimizing the porous structure and electrical conductivity of the resulting hybrid structure. The immobilization of Co-Al-LDH on hybrid MnO2/rG-O network is more effective in enhancing its electrode activity compared with that of on pure rG-O network. The Co-Al-LDH-rG-O-MnO2 nanohybrid deliveres a greater specific capacitance than does MnO2-free Co-Al-LDH-rG-O nanohybrid. The beneficial effect of MnO2 incorporation on the electrode performance of nanohybrid is more prominent for higher current density and faster scan rate, underscoring the significant enhancement of the electron transport of Co-Al-LDH-rG-O. This is supported by electrochemical impedance spectroscopy. The present study clearly demonstrates the usefulness of the porously assembled hybrid network of graphene and metal oxide nanosheets as an effective platform for exploring efficient LDH-based functional materials.