A facile hard-templating synthesis of mesoporous spinel CoFe2O4 nanostructures as promising electrocatalysts for the H2O2 reduction reaction

Abstract

Mesoporous spinel cobalt ferrite (CoFe₂O₄) nanostructures were synthesized via a facile Al₂O₃-assisted hard-templating (HT) strategy. Their physicochemical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray spectra (SEM-EDS), X-ray photoelectron spectra (XPS) and nitrogen sorption measurements. Their electrocatalytic performances towards H₂O₂ reduction reaction (HRR) were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) tests. The obtained CoFe₂O₄ materials exhibit a superior mesoporous nanostructure with a particle size of around 20 nm, a specific surface area (SSA) of 140.6 m² g⁻¹ and a mesopore volume of 0.2410 cm³ g⁻¹, which favor their desirable electrocatalytic activity. A current density of 123 mA cm⁻² at −0.39 V (vs. Hg/HgO) in 3 M NaOH and 0.5 M H₂O₂ electrolytes was delivered for HRR. Moreover, the CoFe₂O₄ electrode exhibits a good stability for the catalytic reaction, showing the promising applications for H₂O₂-based alkaline fuel cells (AFCs).