Investigation of electrochemical performance of the biosynthesized α-Fe2O3 nanorods

Abstract

This study concerns with the development of a facile method for the biosynthesis of α-Fe2O3 nanorods through green method with an extract from Persea Americana seeds and the potential use of these nanords in the electrochemical applications. The α-Fe2O3 biosynthesized with an extract from Persea Americana seeds thereby was studied by the means of X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), Ultraviolet–Visible (UV–vis) analysis, Fourier Transform Infra-Red (FT-IR) spectroscopy, Mössbauer spectroscopy and Cyclic voltammetry. X-ray diffraction (XRD) pattern of the sample determined the crystal structure of α-Fe2O3 nanorods. Transmission Electron Microscopy (TEM) measurements showed a nanorod-based morphology with average diameter of 50 nm and length of 400 nm. FTIR spectrospy spectrum confirmed the phase purity and chemical bond for the sample. The energy band gap Eg value obtained for α-Fe2O3 nanorods based on UV vis spectrum was 2.7 eV. Mössbauer results confirmed the weak ferromagnetic behaviour of the sample as well as the oxidization state. Cyclic voltammetry measurements of α-Fe2O3 nanorods sample coated on glassy carbon electrode (GCE) showed two oxidation peaks at 0.62 V and 0.88 V associated with reversible multi step oxidation of Fe to FeO and then Fe2O3. Electrochemical impedance spectroscopy studies revealed minimum charge transfer resistance Rct value, suggesting that α-Fe2O3 nanorods prepared has good conductivity and can be used in electrochemical energy storage application.