title: Reduced graphene oxide (RGO)-supported NiCo₂O₄ nanoparticles: an electrocatalyst for methanol oxidation.
abstract: 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.
authors.affiliation: Applied Materials Institute for BIN Convergence (BK Plus Global Team), Department of BIN Fusion Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea. namhk99@naver.com.
authors.forename: Ashok Kumar
authors.initials: AK
authors.lastname: Das
authors.forename: Rama K
authors.initials: RK
authors.lastname: Layek
authors.forename: Nam Hoon
authors.initials: NH
authors.lastname: Kim
authors.forename: Daeseung
authors.initials: D
authors.lastname: Jung
authors.forename: Joong Hee
authors.initials: JH
authors.lastname: Lee