A hydrothermal synthesis of porous Pt/NiO/graphene nanocomposite modified glassy carbon electrode and its application in methanol electro-oxidation

The conversion of chemical energy into electrical energy became more important due to the increase in the use of electricity in recent years [1]. The exhaust of fossil fuels and the accompanying environmental pollution have triggered significant interests in developing novel electrode materials for sustainable and clean energy devices. Direct methanol fuel cells (DMFC) have the advantages of high efficiency, low operating temperature, and low pollutant emission, and they are considered as promising power sources [2]. In this work, a glassy carbon electrode was modified with a new porous Pt/NiO/graphene. At first, the glassy carbon electrode surface was cleaned mechanically by polishing with 0.05 μm alumina powder in water slurry on micro cloth pads and rinsed thoroughly with distilled, deionized water before modification. Then, the fresh GC electrode was modified with NiO/graphene which has been prepared successfully by the hydrothermal method. The Pt nanostructures were electrochemically deposited on the surface of the modified electrode under successive scans of cyclic voltammetry in 0.5 M H2SO4. The electrochemical properties of the catalysts were evaluated through electrochemical experiments. Structural characterization of the modified electrode was carried out by using electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD( and scanning electron microscopy (SEM). The electro-oxidation of methanol in 0.1 M NaOH was studies using cyclic voltammetric method. In the optimal condition, the modified electrode exhibits an excellent electrocatalytic activity towards methanol oxidation in the alkaline medium with a high electrochemical active surface areas (ECSAs) and an acceptable stability.