Enhanced glucose electrooxidation at a binary catalyst of manganese and nickel oxides modified glassy carbon electrode

A novel binary electrocatalyst fabricated from manganese and nickel oxides nanoparticles (MnO x and NiO x), prepared by electrodeposition, is proposed as an anode for an amplified electrochemical oxidation of glucose in NaOH solutions. Cyclic voltammetry and scanning electron microscopy images were used to characterize these electrocatalysts. It has been found that the electrocatalytic activity critically depends on the order of the deposition of the two oxides. The NiO x/MnO x/GC electrode (MnO x deposited first) showed a superior electrocatalytic activity towards glucose oxidation compared to NiO x/GC, MnO x/GC or MnO x/NiO x/GC electrodes (NiO x deposited first). The extraordinary activity obtained at the NiO x/MnO x/GC electrode is attributed to the compilation of the better adsorption of glucose molecules on the MnO x sites and the increase of conductivity of the NiO x due to the increase of Ni 3+ content. The results lead us to conclude that there is a synergism between the two oxides towards the electrooxidation of glucose. © 2012 Elsevier B.V. All rights reserved.