Abstract
Graphene (Gr) modified glassy carbon (GCE) electrode with sequentially electrodeposited nickel oxide nanoparticles (NiOx) were prepared as effective and stable electrode for electrochemical oxidation of glucose. The electrochemical behavior of the thus prepared electrode towards glucose was examined by voltammetric techniques. The NiOx/Gr/GCE electrode was prepared by casted Gr onto an electrochemically activated GCE then NiOx was deposited either from nickel bath containing glucose as additive or not. The thus modified electrode was applied for the electrooxidation of glucose in alkaline medium. The effect of loading level of nickel of modified electrode were investigated as well. Furthermore, the NiOx/Gr/GCE electrode was morphologically characterized using scanning electron microscopy (SEM). The elemental composition is probed using energy-dispersive X-ray spectroscopy (EDX). The crystallographic orientation is examined using X-Ray diffraction (XRD) technique. The embedding of NiOx in the Gr enhanced their activity and stability for glucose oxidation reaction. Moreover, the best electrocatalytic activity and stability for glucose was obtained at NiOx (Glu)/Gr/GCE fabricated from nickel bath containing glucose as compared with the unmodified GCE electrode and NiOx /Gr/GCE in nickel bath-glucose free. This enhancement is attributed to a synergistic effect between NiOx (Glu) and Gr, where the NiOx improve the electrochemical behavior via the formation of Ni3+ (NiOOH). The stability of the electrode is enhanced by using grapheme as a substrate for the nickel oxyhydroxide (NiOOH).