An easy, low-cost, repeatable seed-mediated growth approach in solvothermal condition has been proposed to synthesize bimagnetic spinel ferrite core-shell heterostructures in the 10-20 nm particle size range. Cobalt ferrite and manganese ferrite nanoparticles (CoFeO and MnFeO) have been coated with isostructural spinel ferrites like maghemite/magnetite, MnFeO, and CoFeO with similar cell parameters to create different heterostructures. The conventional study of the structure, morphology, and composition has been combined with advanced techniques in order to achieve details on the interface at the nanoscale level. Clear evidence of the heterostructure formation have been obtained (i) indirectly by comparing the Fe Mössbauer spectra of the core-shell samples and an ad hoc mechanical mixture and (ii) directly by mapping the nanoparticles' chemical composition by electron energy loss spectroscopy (EELS) and energy-dispersive X-ray spectroscopy (EDX) in the scanning transmission electron microscopy mode (STEM). In addition, chemical-sensitive electron tomography in STEM-EDX mode has been applied in order to obtain detailed 3D images with a sub-nanometer spatial resolution.
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http://dx.doi.org/10.1021/acsnano.7b02349 | DOI Listing |
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January 2025
School of Resources, Environment and Materials, Guangxi University, Nanning, Guangxi, 530004, China.
The construction of coupled electrolysis systems utilizing renewable energy sources for electrocatalytic nitrate reduction and sulfion oxidation reactions (NORR and SOR), is considered a promising approach for environmental remediation, ammonia production, and sulfur recovery. Here, a simple chemical dealloying method is reported to fabricate a hierarchical porous multi-metallic spinel MFeO (M═Ni, Co, Fe, Mn) dual-functional electrocatalysts consisting of Mn-doped porous NiFeO/CoFeO heterostructure networks and Ni/Co/Mn co-doped FeO nanosheet networks. The excellent NORR with high NH Faradaic efficiency of 95.
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January 2025
Department of Chemistry, College of Basic Sciences, Yadegar-E-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran.
This study presents the development and characterization of manganese ferrite (MnFeO)-based nanocomposites with graphite oxide (GO) and chitosan (CS) for efficient dye removal from textile wastewater and aqueous solution. Comprehensive characterization was performed using FT-IR, Raman, XRD, BET, SEM, DRS and Zeta potential techniques. XRD analysis confirmed the cubic spinel structure of MnFeO, with characteristic peaks at 2θ = 32, 35, 48, 53, 62, and 64°.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA.
Additive manufacturing (AM) of magnetic materials has recently attracted increasing interest for various applications but is often limited by the high cost and supply chain risks of rare-earth-element (REE) magnetic precursors. Recent advances in nanomanufacturing have enabled the development of rare-earth-free (REF) magnetic materials, such as spinel ferrites, hexaferrites, MnAl, MnBi, Alnico, FePt, and iron oxides/nitrides, which offer promising alternatives for printing high-performance magnetic devices. This review provides a detailed overview of the latest developments in REF magnetic materials, covering both synthesis strategies of REF magnetic materials/nanomaterials and their integration into AM processes.
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December 2024
Department of Mining Engineering, Faculty of Engineering, University of Birjand, Birjand, Iran.
To tackle the challenges of increasing the efficiency of photocatalysts, a ternary magnetic heterojunction photocatalyst containing spinel cobalt and zinc ferrites, and zeolite (CZZ) was designed and fabricated. The physicochemical properties of the novel photocatalyst were verified using characterization techniques such as XRD, FT-IR, FE-SEM, EDS mapping, N adsorption-desorption, VSM, PL, and UV-Vis DRS. The CZZ photocatalyst exhibited a significant Cr (VI) reduction rate of 0.
View Article and Find Full Text PDFChemosphere
December 2024
Laboratorio de Investigaciones Ambientales Zonas Áridas, Departamento de Ingeniería Mecánica, Facultad de Ingeniería, Universidad de Tarapacá, Avda. General Velásquez, 1775, Arica, Chile.
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal).
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