Electrocatalytic glucose oxidation at binary catalyst of nickel and manganese oxides nanoparticles modified glassy carbon electrode: Optimization of the loading level and order of deposition

This work addresses the electrocatalytic activity of a new catalyst composed of nickel and manganese binary oxides, prepared by electrodeposition, toward glucose electro-oxidation in alkaline medium. Cyclic voltammetry, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to characterize those electrocatalysts. It has been found that the electrocatalytic activity critically depends on the loading level and the order of deposition of the two oxides; the NiOx/MnOx/GC electrode (MnOx deposited first) showed an excellent electrocatalytic activity and stability toward glucose oxidation compared to NiOx/GC, MnOx/GC or MnOx/NiOx/GC electrodes (NiOx deposited first). At the present work conditions, it has found that, the optimum loading level is 60 cycles of MnOx followed by 10 min deposition of nickel. At this loading level, it has been found that, the relation between Ip/v1/2 function and scan rate gives the characteristic feature of a catalytic process.