In the last decade, research on the synthesis and characterization of nanosized ferrites has highly increased and a wide range of new applications for these materials have been identified. The ability to tailor the structure, chemical, optical, magnetic, and electrical properties of ferrites by selecting the synthesis parameters further enhanced their widespread use. The paper reviews the synthesis methods and applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanoparticles, with emphasis on the advantages and disadvantages of each synthesis route and main applications. Along with the conventional methods like sol-gel, thermal decomposition, combustion, co-precipitation, hydrothermal, and solid-state synthesis, several unconventional methods, like sonochemical, microwave assisted combustion, spray pyrolysis, spray drying, laser pyrolysis, microemulsion, reverse micelle, and biosynthesis, are also presented. MFe2O4 (M = Co, Cu, Mn, Ni, Zn) nanosized ferrites present good magnetic (high coercivity, high anisotropy, high Curie temperature, moderate saturation magnetization), electrical (high electrical resistance, low eddy current losses), mechanical (significant mechanical hardness), and chemical (chemical stability, rich redox chemistry) properties that make them suitable for potential applications in the field of magnetic and dielectric materials, photoluminescence, catalysis, photocatalysis, water decontamination, pigments, corrosion protection, sensors, antimicrobial agents, and biomedicine.

Recent Advances in Synthesis and Applications of MFe2O4 (M = Co, Cu, Mn, Ni, Zn) Nanoparticles

Cobalt ferrite nanoparticles and nanocomposites: Photocatalytic, antimicrobial activity and toxicity in water treatment

Heterogeneous Fenton-like oxidation is one of the advanced oxidation processes (AOPs) that can successfully remove a large number of pollutants from water. Among various materials used as catalysts in this process, spinel ferrite nanoparticles (SFs) have received increasing attention in recent years because of their unique physicochemical properties, low-cost, good catalytic activity and interesting bandgap. In the same vein, their magnetic properties allow them to be easily, rapidly and inexpensively separated from the reaction medium. The present review highlights the unique structure and properties of different spinel ferrite nanoparticles, their synthesis approaches and their applications as a catalyst in heterogeneous Fenton-like and photo-Fenton-like oxidation. It was demonstrated that MFe2O4 have unlimited ability as catalysts in both heterogeneous Fenton-like and photo-Fenton-like oxidation. Thus, it can be deduced that their catalytic activity depends on the nature of divalent metal M, synthesis method, annealing temperature, pollutant nature and concentration, H2O2 concentration, pH, temperature and light source for photo-Fenton-like oxidation.

Spinel ferrites nanoparticles: Synthesis methods and application in heterogeneous Fenton oxidation of organic pollutants – A review

Activation of sulfite autoxidation with CuFe2O4 prepared by MOF-templated method for abatement of organic contaminants.

One-step preparation of reduced graphene oxide aerogel loaded with mesoporous copper ferrite nanocubes: A highly efficient catalyst in microwave-assisted Fenton reaction.

Comparative studies on the impact of synthesis methods on structural, optical, magnetic and catalytic properties of CuFe2O4

Nanocrystallites of pure and mixed ternary ferrites, NiFe2O4 (NiF), CuFe2O4 (CuF), CoFe2O4 (CoF), Ni0.5Cu0.5Fe2O4 (CuNiF), Ni0.5Co0.5Fe2O4 (NiCoF), and Cu0.5Co0.5Fe2O4 (CuCoF) were prepared using the auto-combustion method employing urea as a fuel. The obtained materials were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron miscroscopy (TEM), scanning electron microscopy (SEM), and BET techniques. The elemental composition of the prepared samples was checked by X-ray fluorescence (XRF) analysis. XRD indicated that the as-synthesized samples exhibit a pure spinel crystal structure. The samples have crystallite sizes ranged from 12 to 47 nm. SEM and TEM analyses showed almost spherical morphology for all ferrite particles. The M–H curves recorded using the VSM (vibrating sample magnetometer) technique showed ferromagnetic hysteresis loop for all the samples investigated. The ferrite samples were tested to be used as a supercapacitor electrode material. It is found that the measured specific capacitance of the ferrite electrodes increases according to CuCoF > NiCoF > CoF > NiCuF > CuF > NiF. The CuCoF sample showed the greatest specific capacitance of 220 F/g at discharging current density l of A/g with, an energy density of 34.72 Wh/kg and power density of 605 W/kg. The magnetic properties were also measured for the obtained nanoparticles.

Studies on characterization, magnetic and electrochemical properties of nano-size pure and mixed ternary transition metal ferrites prepared by the auto-combustion method


 Cobalt ferrite (CoFe2O4) nanoparticles were synthesized through three different routes (chemical co-precipitation, ceramic, and sol-gel). The products were characterized by XRD, SEM, TEM, Raman spectroscopy, FTIR, photoluminescence (PL), BET, XPS, vibrating sample magnetometer (VSM). The X-ray analysis validates the spinel structure of the samples with particle sizes between 21 – 36 nm. XPS revealed the impact of the preparation route on cation distribution at the tetrahedral and octahedral sites in spinel ferrite lattice. All ferrite surfaces exhibit a mesoporous structure with a surface area between 25 – 99 m2/g. The results show that the prepared samples exhibit either ferromagnetic or super-paramagnetic behavior. The ferrite samples showed a photocatalytic performance under visible light. The present work demonstrates that each of the particle size and cation distribution is effective in controlling the structural, magnetic, and optical properties. The results obtained reveal that this kind of CoFe2O4 spinel ferrite nanoparticles has promising applications in magnetic designs and water treatment fields.

S. S. Selima

Papers

Comparative studies on the impact of synthesis methods on structural, optical, magnetic and catalytic properties of CuFe2O4

Studies on characterization, magnetic and electrochemical properties of nano-size pure and mixed ternary transition metal ferrites prepared by the auto-combustion method

Structural, Magnetic, Optical Properties and Photocatalytic Activity of Nanocrystalline Cobalt Ferrite Prepared by Three Different Methods