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The design and development of cheap, highly active, and durable non-platinum (Pt)-based electrocatalysts for methanol electrooxidation is highly desirable, but is a challenging task. In this paper, we demonstrate the application of a hydrothermally synthesized NiCo₂O₄-reduced graphene oxide (RGO) composite as an electrocatalyst for the electrochemical oxidation of methanol in alkaline pH. The physicochemical properties of the NiCo₂O₄-RGO composite were investigated via Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements. The physical characterization methods confirm the deposition of NiCo₂O₄ nanoparticles on the RGO surface. The TEM image shows that the NiCo₂O₄ nanoparticles with an average size of ∼10 nm are distributed over the RGO surface. Compared to RGO and NiCo₂O₄ nanoparticles, the NiCo₂O₄-RGO-based electrode shows excellent electrocatalytic activity for the oxidation of methanol in alkaline pH. On the NiCo₂O₄-RGO-based electrode, the oxidation of methanol occurs at ∼0.6 V with a higher catalytic current density, and the response is highly stable. The excellent electrocatalytic activity of the NiCo₂O₄-RGO composite is attributed to the synergistic effects between the NiCo₂O₄ nanoparticles and RGO. Since the NiCo₂O₄-RGO composite shows a highly stable response during methanol oxidation reaction, it is a very promising material to be used as an electrocatalyst in the development of high performance non-Pt based alkaline fuel cells.

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Synthesis of reduced graphene oxide (RGO) from graphite oxide (GO) usually involves the use of some harmful reducing agents. Here, we report a simple approach for the reduction of GO at room temperature using a mixture of potassium iodide and hydrochloric acid. The reduction of GO involves (a) iodide mediated epoxide ring-opening, resulting in hydroxyl groups and dehydration to the corresponding olefins, (b) hydroxyl group substitution by iodide ions, and (c) elimination of iodide ions on the surface. The as-synthesized RGO has an electrical conductivity of 1251 S m À1 and an excellent electrocatalytic activity. The electrocatalytic activity of RGO towards the electrochemical reduction of oxygen and the oxidation of hydrazine was investigated. The RGO-based electrode showed pronounced electrocatalytic activity towards the reduction of oxygen and the oxidation of hydrazine in 0.1 M KOH. At alkaline pH, the reduction of oxygen and oxidation of hydrazine were observed at À0.35 and 0.5 V, respectively. In comparison with the bare glassy carbon (GC) electrode, a spectacular decrease in the overpotential and considerable increase in the oxidation peak current for hydrazine were observed on the RGO-based electrode without using any redox mediator. The RGO-based platform is highly sensitive towards the electrochemical oxidation of hydrazine and reproducible results were obtained. Moreover, the RGO-based electrode showed excellent operational and long time storage stabilities. The sensitivity of the electrode was calculated to be 0.137 AE 0.02 mA mM À1 .