Facile synthesis of iron titanate/nitrogen-doped graphene on Ni foam as a binder-free electrocatalyst for oxygen evolution reaction

Abstract

• A three-dimensional Fe 2 TiO 5 /nitrogen-doped graphene nanocomposite is prepared using a simple, cheap and fast chemical bath deposition method. • Structural and physical characterizations of the prepared electrocatalyst are performed by different analysis methods. • The fabricated binder-free electrode, by coating the prepared composite on nickel foam, is applied for studying the oxygen evolution reaction. • The prepared electrode showed high electrocatalytic efficiency for oxygen evolution reaction in alkaline medium. • The electrode provided an overpotential of 264.15 mV at 10 mA cm −2 and the Tafel slope is 35 (mV/dec) and also showed long-term stability in alkaline media. Given the growing need for renewable energy and related technologies, researches have shifted to develop low-cost, stable, high-efficiency electrocatalysts in clean energy generation reactions such as water electrolysis. In the present paper, a three-dimensional Fe 2 TiO 5 /nitrogen-doped graphene (3D FTO/NG) nanocomposite is prepared using a simple, cheap and fast method, called chemical bath deposition (CBD). Structural and physical characterizations of the prepared electrocatalysts are performed by different methods such as Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform InfraRed spectra (FT-IR), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Raman spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The fabricated binder-free 3D FTO/NG, 3D NG and 3D G on nickel foam (NF) electrodes, were applied to study oxygen evolution reaction (OER) in alkaline medium. Among these electrodes, the 3D FTO/NG electrocatalyst, has an overpotential of 264.15 mV at 10 mA cm −2 and its Tafel slope was 35 (mV/dec). Its long-term stability and excellent performance are due to the simultaneous effect of nitrogen doping and presence of metal oxide nanoparticles, which helped to increase the number of active sites for reaction, adsorption of hydroxide ions and electrode conductivity.