Sugar-cubic Fe2O3/nitrogen-doped graphene nanocomposite as high-performance anode material for oxygen evolution reaction

Abstract

Industrial application of water electrolysis has called for the development of oxygen evolution electrocatalysts that are low-cost, stable and have low overpotential. Substituting the precious metal catalysts with more accessible transition metal oxide such as Fe2O3 is a key solution for applications in water electrolysis. Here, we show an efficient modified electrode for oxygen evolution, which be developed by co-electrodeposition of graphene oxide and Fe2O3 nanoparticles directly onto macroporous nickel foam substrate. Then, using an electrochemical procedure, in-situ electro-polymerization of pyrrole and graphene oxide reduction are performed on the electrode surface. The sugar-cubic Fe2O3 nanoparticles are also prepared by the hydrothermal method. The morphology and structure of the Fe2O3 nanoparticles and Fe2O3/ graphene nanocomposites are characterized by Field-Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infra-Red spectroscopy (FT-IR), X-Ray Diffraction (XRD), Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS) methods. Moreover, the OER activities of the synthesized catalysts are investigated by using Linear Sweep Voltammetry (LSV), Chronopotentiometry (CP) and Electrochemical Impedance Spectroscopy (EIS) methods. The electrocatalytic activity of the sugar-cubic Fe2O3/nitrogen-doped graphene nanocomposite prepared by hydrothermal method in alkaline media shows outstanding advantages, so that its over potential was 313 mV and its Tafel slope was 81 mV/dec.