High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction

Abstract Water oxidation, or the oxygen evolution reaction (OER), is the half-reaction that limits the efficiency of overall water splitting and represents a major bottleneck in the production of sustainable hydrogen fuel. Developing efficient, cost-effective, and environmentally benign OER catalyst...

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Main Authors: Freshteh Gheybi, Majid Rashidi-Huyeh, Mohammad Reza Mohammadi
Format: Article
Language:English
Published: Springer 2025-07-01
Series:Discover Materials
Subjects:
Online Access:https://doi.org/10.1007/s43939-025-00310-x
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author Freshteh Gheybi
Majid Rashidi-Huyeh
Mohammad Reza Mohammadi
author_facet Freshteh Gheybi
Majid Rashidi-Huyeh
Mohammad Reza Mohammadi
author_sort Freshteh Gheybi
collection DOAJ
description Abstract Water oxidation, or the oxygen evolution reaction (OER), is the half-reaction that limits the efficiency of overall water splitting and represents a major bottleneck in the production of sustainable hydrogen fuel. Developing efficient, cost-effective, and environmentally benign OER catalysts is therefore critical for advancing green energy technologies. In this study, magnetite and cobalt–iron oxide nanoparticles with varying cobalt contents were synthesized via a green co-precipitation method using Seidlitzia rosmarinus plant extract, and their properties were compared with those of counterparts prepared by a conventional chemical route. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) revealed that green-synthesized samples exhibited a more amorphous character and contained hematite phases, while chemically synthesized materials were more crystalline and magnetite-rich. Field emission scanning electron microscopy (FESEM) and elemental mapping confirmed homogeneous cobalt distribution across all samples. Magnetic measurements via vibrating sample magnetometry (VSM) showed significantly reduced saturation magnetization in green-synthesized samples, attributed to cobalt substitution in the hematite structure, which induced paramagnetic behavior. Electrochemical characterization revealed superior OER performance for the green-synthesized cobalt–iron oxide nanoparticles, with the best sample (20 wt% Co) delivering a current density of 64 mA·cm⁻2 at 1.1 V vs. NHE and an overpotential of 275 mV at 10 mA·cm⁻2. The enhanced catalytic activity is ascribed to the amorphous microstructure, increased surface roughness, and synergistic electronic interactions between Fe and Co. These results underscore the potential of plant-extract-mediated green synthesis as a viable strategy for fabricating high-performance transition metal oxide catalysts for water oxidation and hydrogen production.
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spelling doaj-art-d56eeb3ed1c846a4883d1850ccc1bad42025-08-20T03:42:03ZengSpringerDiscover Materials2730-77272025-07-015111410.1007/s43939-025-00310-xHigh catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reactionFreshteh Gheybi0Majid Rashidi-Huyeh1Mohammad Reza Mohammadi2Department of Physics, University of Sistan and BaluchestanDepartment of Physics, University of Sistan and BaluchestanDepartment of Physics, University of Sistan and BaluchestanAbstract Water oxidation, or the oxygen evolution reaction (OER), is the half-reaction that limits the efficiency of overall water splitting and represents a major bottleneck in the production of sustainable hydrogen fuel. Developing efficient, cost-effective, and environmentally benign OER catalysts is therefore critical for advancing green energy technologies. In this study, magnetite and cobalt–iron oxide nanoparticles with varying cobalt contents were synthesized via a green co-precipitation method using Seidlitzia rosmarinus plant extract, and their properties were compared with those of counterparts prepared by a conventional chemical route. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) revealed that green-synthesized samples exhibited a more amorphous character and contained hematite phases, while chemically synthesized materials were more crystalline and magnetite-rich. Field emission scanning electron microscopy (FESEM) and elemental mapping confirmed homogeneous cobalt distribution across all samples. Magnetic measurements via vibrating sample magnetometry (VSM) showed significantly reduced saturation magnetization in green-synthesized samples, attributed to cobalt substitution in the hematite structure, which induced paramagnetic behavior. Electrochemical characterization revealed superior OER performance for the green-synthesized cobalt–iron oxide nanoparticles, with the best sample (20 wt% Co) delivering a current density of 64 mA·cm⁻2 at 1.1 V vs. NHE and an overpotential of 275 mV at 10 mA·cm⁻2. The enhanced catalytic activity is ascribed to the amorphous microstructure, increased surface roughness, and synergistic electronic interactions between Fe and Co. These results underscore the potential of plant-extract-mediated green synthesis as a viable strategy for fabricating high-performance transition metal oxide catalysts for water oxidation and hydrogen production.https://doi.org/10.1007/s43939-025-00310-xWater SplittingMagnetite nanoparticlesCobalt-iron oxide nanoparticlesGreen method
spellingShingle Freshteh Gheybi
Majid Rashidi-Huyeh
Mohammad Reza Mohammadi
High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
Discover Materials
Water Splitting
Magnetite nanoparticles
Cobalt-iron oxide nanoparticles
Green method
title High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
title_full High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
title_fullStr High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
title_full_unstemmed High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
title_short High catalytic activity of iron and cobalt-iron oxide nanoparticles synthesized via a green method for the oxygen-evolution reaction
title_sort high catalytic activity of iron and cobalt iron oxide nanoparticles synthesized via a green method for the oxygen evolution reaction
topic Water Splitting
Magnetite nanoparticles
Cobalt-iron oxide nanoparticles
Green method
url https://doi.org/10.1007/s43939-025-00310-x
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AT majidrashidihuyeh highcatalyticactivityofironandcobaltironoxidenanoparticlessynthesizedviaagreenmethodfortheoxygenevolutionreaction
AT mohammadrezamohammadi highcatalyticactivityofironandcobaltironoxidenanoparticlessynthesizedviaagreenmethodfortheoxygenevolutionreaction