Synthesis of Graphite Oxide/Cobalt Molybdenum Oxide Hybrid Nanosheets for Enhanced Electrochemical Performance in Supercapacitors and the Oxygen Evolution Reaction

Abstract

Reduced graphite oxide (rGO)/cobalt molybdenum oxide (CoMoO4) hybrid nanosheets (NSs) have been prepared by using the hydrothermal method followed by detailed characterization with X-ray diffraction, electron microscopy, Raman and FTIR spectroscopy. The unusual rGO/CoMoO4 hybrid NSs allow the electrochemical reactions of electrodes for supercapacitors. Therefore, an excellent specific capacitance (ca. 450 F/g at 2 mV/s) and stability performance of the rGO/CoMoO4 hybrid NSs were observed in alkaline medium (i. e. 5 M KOH electrolyte). The rGO/CoMoO4 hybrid NSs show five times higher specific capacitance compared to pure CoMoO4 NSs. The cyclic stability of the rGO/CoMoO4 hybrid NSs reveals retention of approximately 98 % of the initial capacitance after 1500 cycles. Moreover, the rGO/CoMoO4 hybrid electrocatalyst shows higher oxygen evolution activity than CoMoO4 NSs in 0.1 M KOH versus Ag/AgCl. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), linear sweep voltammetry (LSV), and chronoamperometric (CA) measurements strongly support the enhanced electrochemical performance of the rGO/CoMoO4 hybrid NSs.