Electrocatalytic glucose oxidation on electrochemically oxidized glassy carbon modified with nickel oxide nanoparticles

Abstract

In this work, we study the effect of anodic oxidation of glassy carbon (GC) on the deposition of nickel oxide (NiOx) nanoparticles and the electrocatalytic oxidation of glucose on the anodically oxidized GC modified with the NiOx. The GC is pretreated by anodic oxidation in 0.1M H2SO4 solution at different anodic potentials for different time periods. Different shape and size of NiOx nanoparticles are obtained when NiOx is deposited on anodically oxidized GC electrode. The purpose of the anodic oxidation is to manipulate the GC surface such that it gives higher surface concentration of C–O functional groups and higher surface area which leads to an extraordinary increase in the activity of NiOx towards glucose electrooxidation. Glucose electrooxidation is conducted in alkaline medium at GC/NiOx (GC is untreated) and GCox/NiOx (GC is treated) electrodes. Cyclic voltammetry (CV), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) are used for characterization of the above electrodes. The GCox/NiOx shows an excellent electrocatalytic activity toward glucose oxidation compared to GC/NiOx. The enhancement of the electrocatalytic activity obtained at the GCox/NiOx is discussed in the light of the obtained differences in characteristics of GCox/NiOx and increase in the surface concentration of C–O functional groups.