Ferrita de cálcio ortorrômbica : impacto da metodologia de síntese nas características microestruturais e eletroquímicas

Abstract

The overall objective of this work is to investigate the production of calcium ferrite through three different synthesis methods: Sol-gel (SG), Solution Blow Spinning (SBS), and High Energy Milling (HEM), and to evaluate which method results in the best oxygen evolution reaction (OER). The specific objectives include the synthesis of ferrites with the stoichiometry of CaFe2O4 using the solgel proteic technique, Solution Blow Spinning (SBS), and High Energy Milling (HEM). The microstructure was analyzed using X-ray diffraction (XRD), infrared spectroscopy (FTIR), Raman spectroscopy, Mössbauer spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrochemical nature of the samples was characterized through linear sweep voltammetry (LSV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). It was observed that the morphology of CaFe2O4 produced via SBS exhibited the best catalytic response for OER compared to the SG and HEM morphologies, achieving current density generation performance at 10 mA cm-2 with an overpotential (η) of 300 mV, a Tafel slope of 41 mV dec-1, and specific activity (SA) of 10.56 mA cm-2.