Characterization Of Cobalt Ferrite Nanoparticles Research Articles

Simple Synthesis and Characterization of Cobalt Ferrite Nanoparticles for the Successful Adsorption of Indigo Carmine Dye from Aqueous Media

Indigo carmine dye falls into the category of toxic chemicals, potentially leading to irritation and allergic reactions in certain individuals. Thus, this study employed the Pechini sol–gel strategy to easily produce CoFe2O4 nanoparticles, which serve as an effective adsorbent for the disposal of indigo carmine dye from aqueous solutions. The maximum adsorption capacity of CoFe2O4 for indigo carmine dye was determined to be 421.94 mg/g. The synthesized CoFe2O4 nanoparticles exhibited an average crystallite size of 18.75 nm. SEM analysis revealed that these nanoparticles were nearly spherical, with an average grain size of 198.32 nm. Additionally, TEM analysis indicated a fully agglomerated spherical morphology for the CoFe2O4 sample, with an average diameter of 15.37 nm. The EDS spectrum confirmed that the synthesized CoFe2O4 nanoparticles consisted of Co, Fe, and O elements, with respective weight percentages of 17.82%, 49.46%, and 32.72%. The removal of indigo carmine dye by the synthesized CoFe2O4 is spontaneous, chemical, exothermic, closely fitting the pseudo-second-order kinetic model, and demonstrating a strong concordance with the Langmuir equilibrium isotherm.

Characterization of cobalt ferrite nanoparticles obtained by various synthesis methods and comparison with the Raman spectra of other ferrites and some cubic oxide spinels

Characterization of cobalt ferrite nanoparticles obtained by various synthesis methods and comparison with the Raman spectra of other ferrites and some cubic oxide spinels

A deep insight into the magnetic properties of cobalt ferrite by non-equilibrium thermodynamics with internal variables

The paper presents for the first time an in-depth theoretical magnetic characterization of cobalt ferrite nanoparticles (CoFe2O4) by using the thermodynamic approach of non-equilibrium with internal variables. Considering that a complete knowledge of the structure and properties is crucial to design a material for a specific application, a complete thermodynamic characterization of magnetic properties turns out to be useful for a plethora of technological and biomedical purposes. The non-equilibrium thermodynamics is exploited to calculate the internal variables as a function of the perturbation frequencies. Our results allow to fully characterizing the investigated material in terms of magnetization by orientation and by deformation (M(1) and M(0)), magnetic field B(1), magnetization displacement current (E), entropy production (σ), phenomenological coefficients (L(0,0) and L(1,1)) and state coefficients (a(0,0), a(1,1)). CoFe2O4 has been selected as a proof of concept; our theoretical investigation and parameters are applicable to all the para- and ferromagnetic materials, including biomolecules and biological tissues allowing to compare healthy and pathological behavior, subjected to a variable magnetic field for which it is possible to conceive a linear approximation.

Morphologic, structural, and magnetic characterization of cobalt ferrite nanoparticles synthesized at different temperatures

In this study we report on the synthesis and characterization of cobalt ferrite (CoFe2O4) nanoparticles (NPs), synthesized by chemical co-precipitation in alkaline medium. Two samples were synthesized at two different temperatures, 35 and 90 oC. Both samples were characterized by Transmission Electron Microscopy (TEM), x-ray diffraction (XRD), and room-temperature (RT) magnetization. Two samples showed superparamagnetic behavior (SPM) at RT. TEM reveals morphological mean diameter increasing 5.8 nm to 10.4 nm, with the increase of the co-precipitation temperature. XRD confirm the inverse cubic spinel structure. The RT magnetization curves were analyzed by the first-order Langevin function averaged out by a lognormal distribution function of magnetic moments. This analysis showed saturation magnetization and magnetic moment increases from 60.2 to 74.8 emu/g and from 3.9 x 103 to 8.2 x 103 mB, respectively.

Immobilization of diastase on PVA- CoFe2O4 nanocomposite film for improving stability and recycling

Enzyme immobilization on a suitable support is one of the strategies used to improve enzyme stability and recovery. In present communication, PVA-CoF2O4 nanocomposite film has been used as a support to develop highly active, stable and magnetically separable immobilized diastase. For preparing magnetically separable support, first Cobalt ferrite nanoparticles have been prepared by using co-precipitation method. Prepared nanoparticles have been dispersed in polyvinyl alcohol (PVA) solution to get a PVA-CoFe2O4 film. The detail characterization of cobalt ferrite nanoparticles and PVA-CoFe2O4 film has been carried out. Enzyme diastase has been immobilized on the PVA-CoFe2O4 film and the catalyst activity of immobilized enzyme has been tested in hydrolysis of starch to maltose. The stability of immobilized diastase has found to be higher than free enzyme. Reusability study of the immobilized diastase has been carried out. Improved stability and reusability of immobilised diastase offer the promising applicability as magnetically separable biocatalyst for industry.

Scanning Electron Microscopy and Spectroscopy Characterization of Cobalt Ferrite Nanoparticles by a Facile Hydrothermal Synthesis Method

Scanning Electron Microscopy and Spectroscopy Characterization of Cobalt Ferrite Nanoparticles by a Facile Hydrothermal Synthesis Method

Synthesis and Characterization of Cobalt Ferrite Nanoparticles via Sol-Gel Auto Combustion Method

This article reports the synthesis of cobalt ferrite (CoFe2O4) nanoparticles by low-cost sol-gel auto combustion method. The synthesized CoFe2O4 nanoparticles were characterized using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray (EDX), UV-Visible (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR) and Vibrating Sample Magnetometry (VSM). The XRD pattern inferred the formation of cubic spinel structure with average crystallite size 35.3 nm. The crystallite size was obtained in the range 32-37.5 nm in FESEM analysis. The elemental composition was confirmed using EDX spectroscopy. The presence of spectral lines at positions 465.57 cm-1 and 577.52 cm-1 associated to stretching vibrations of Co-O in octahedral sites and Fe-O in tetrahedral sites confirmed the spinel structure. The magnetic properties such as saturation magnetization (Ms) 67.79 emu/g, coercivity (Oe) 874.76 Oe and remnant (Mr) 29.07 emu/g were obtained from the hysteresis curve. The bandgap 1.409 eV was obtained for synthesized CoFe2O4 using Tauc plot from UV-Vis absorption spectra.

Effect of Reaction pH on Characterization of Co-precipitated Cobalt ferrite Nanoparticles

Effect of Reaction pH on Characterization of Co-precipitated Cobalt ferrite Nanoparticles

Synthesis and characterization of cobalt ferrite nanoparticles prepared by the glycine-nitrate process

In this research, microstructural evolution and magnetic properties of cobalt ferrite spinel (CoFe2O4) were studied. The ferrite was prepared by the glycine-nitrate process (GNP) followed by calcination process, and subsequent high energy mechanical milling. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and vibration sample magnetometery (VSM) methods. The results showed that the desired high purity spinel phase was formed through a complete combustion reaction using the G/N ratio of 1.48. The as-synthesized powder revealed the coercivity and saturation magnetization of 900 Oe and 62.83 emu/g, respectively. The CoFe2O4 phase was stable after calcination at 500 °C for 2 h under argon atmosphere and subsequent milling processes for 2 and 4 h. The highest coercivity value was obtained for the calcined sample (975 Oe), whose average particle size exhibited noticeable conformity with the single magnetic domain size of CoFe2O4 (~ 40 nm). For the 2 h-milled and 4 h-milled samples, the average particle size was below the single magnetic domain size, causing a significant reduction in coercivity values (820 and 770 Oe, respectively). The saturation magnetization was increased negligibly after the calcination process (63.22 emu/g), while it was raised to 71.47 and 73.98 emu/g after 2 and 4 h milling, probably due to the cationic redistribution during milling.

Preparation and characterization of cobalt ferrite nanoparticles with different capping agents and its photocatalyst application

In this investigation we synthesize CoFe2O4 nanoparticles as a highly efficient photocatalyst for degradation of methyl orange. In addition, a green method for synthesis of CoFe2O4 magnetic nanoparticles with spherical morphology is proposed. We also investigated the effect of different carbohydrate sugars such as glucose, lactose and starch on morphology and particle size of nanoparticles. The crystal structures, morphology and chemical properties of the as-synthesized nanoparticles were characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, vibrating sample magnetometer techniques and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of CoFe2O4 was investigated by degradation of methyl orange (MO) as cationic dye in aqueous solution under UV irradiation. The results indicate that about 77% of MO were degraded after 80 min.

Antibacterial properties of copper-substituted cobalt ferrite nanoparticles synthesized by co-precipitation method

Controlled growth and careful characterization of cobalt ferrite nanoparticles for antibacterial applications are challenging. Copper-substituted cobalt ferrite nanoparticles (CuxCo1−xFe2O4), where x=0.0, 0.3, 0.5, 0.7 and 1.0, were synthesized using an economical and simple co-precipitation technique. The crystal structure and antibacterial properties of the samples as a function of Cu-substituted content were systematically studied. With increasing Cu concentration, the nanoparticle size decreased from ∼30 to ∼20nm. The Fourier transform infra-red spectra exhibit two prominent fundamental absorption bands, at ∼595 and 419cm−1. These bands correspond to intrinsic stretching vibrations of metals at tetrahedral and octahedral sites, respectively. The Raman scattering results reveal that increasing the Cu content enhances the local disorder at both tetrahedral and octahedral sub lattices. The results indicate that the substitution of Co with Cu in cobalt ferrite nanoparticles strongly influences the microstructure, crystal structure, and particle diameter, and also improves the antibacterial properties.

Combustion synthesis and characterization of cobalt ferrite nanoparticles

Highly crystalline cobalt nano ferrites have been synthesized by the combustion route using dl-alanine, a racemic mixture of right handed (d) and left handed (l) chemical forms of alpha-alanine, as fuel. The synthesized samples were annealed at two different temperatures, viz. 500°C and 800°C, for 2h to investigate the temperature effect on crystallite size, phase purity, thermal stability, Curie temperature, and magnetic properties. Formation of single-phase spinel nanoparticles in both the as-prepared and annealed conditions has been observed. High saturation magnetization (71.1emu/g) for as-prepared sample and a high coercive field (1400Oe) for the sample annealed at 500°C/2h were obtained.

Synthesis and Characterization of Cobalt Ferrite Nanoparticles

Cobalt ferrite can be synthesized using several techniques. However, to have wide applications in electronic, medical fields etc., the synthesis technique should be simple and inexpensive. The synthesis technique used to prepare nanoparticles should not consume lot of time and energy. Also it should yield narrow particle size distribution and homogeneity in the prepared material. It was observed that surface modification such as with silica coating on the cobalt ferrite will have significant effect on the structural and magnetic properties. It is also observed that, silica coated nanoparticles could be used in biomedical applications (Hong et al., 2013). In this work we have chosen sol-gel method to synthesize pure cobalt ferrite (CoFe2O4) and silica coated (CoFe2O4 / SiO2) nanoparticles. To observe the effect of silicate coating on the structural and magnetic properties of CoFe2O4 we have carried out the present study. CoFe2O4 nanoparticles were synthesized with SiO2 coating and in pure form by sol-gel method. The obtained particle sizes were 24 and 26 nm in both the cases. The X-ray diffraction patterns showed the formation of CoFe2O4 spinel structure without any traces of SiO2 in the prepared samples. The Infrared spectra showed the bands corresponding to tetrahedral and octahedral sites as feature of typical spinel ferrites and also band due to SiO2. The particle size and morphology of CoFe2O4 / SiO2 was found to be uniform but in the case of pure CoFe2O4 somewhat agglomerated which is accounted for magnetization of ferrites. The magnetization value for CoFe2O4 / SiO2 showed a drastic decrease when compared to pure CoFe2O4 due to presence of non-magnetic coating layer.

Preparation and characterization of cobalt ferrite nanoparticles coated with fucan and oleic acid

Cobalt ferrite has attracted considerable attention in recent years due to its unique physical properties such as high Curie temperature, large magnetocrystalline anisotropy, moderate saturation magnetization, large magnetostrictive coefficient, excellent chemical stability and mechanical hardness. In this work we present the preparation, of fucan coated cobalt ferrite nanoparticles by a modified coprecipitation method and the study of their structural, microstructural and magnetic characteristics for their application as a solid support for enzymes immobilization and other biotechnology applications. Aqueous suspensions of magnetic particles were prepared by coprecipitation of Fe(III) and Co(II) in the presence of NaOH, acid oleic and fucan polymer. The X-ray diffraction indicates that the funtionalization does not degrade the core cobalt ferrite. The infrared (FTIR) bands, indicate the functional characteristics of the coating on the cobalt ferrite. Mossbauer spectra at room temperature indicate the presence of a broadened sextet plus a doublet which is typical of superparamagnetic relaxation. For the Co-ferrite uncoated and coated with fucan the doublets have areas of 36.1 % and 40.3 % respectively, indicating the presence of non-interacting particles and faster relaxation time. The Co-ferrite coated with oleic acid and oleic acid plus fucan have areas around 17.5%and 17.1% respectively which indicate a weak superparamagnetic relaxation due to a slow relaxation time. The magnetization measurements of the cobalt ferrite nanoparticles with and without coating confirm that they are superparamagnetic and this behavior is produced by the core nanoparticles rather than the coatings. The cobalt ferrite nanoparticles coated with oleic acid presented the highest magnetization than when coating with fucan.

Synthesis and characterization of cobalt ferrite nanoparticles in hybrid micelles of poly[styrene-block-(ethylene oxide)] and sodium dodecyl sulfate

Cobalt ferrite nanoparticles are synthesized in hybrid micelles of poly[styrene-block-(ethylene oxide)] and sodium dodecyl sulfate in water at room temperature. The nanoparticles are prepared by the chemical precipitation method via the exchange reaction between iron and cobalt salts with sodium dodecyl sulfate and the redox reaction under the action of an aqueous solution of methylamine. As evidenced by small-angle X-ray scattering, transmission electron microscopy, and ferromagnetic resonance examination, cobalt ferrite nanoparticles occurring in hybrid micelles of the block copolymer and sodium dodecyl sulfate are polydisperse (their size is 0.3–50 nm) and ferromagnetic.

Simple Synthesis and Characterization of Cobalt Ferrite Nanoparticles by a Thermal Treatment Method

Crystalline, magnetic, cobalt ferrite nanoparticles were synthesized from an aqueous solution containing metal nitrates and polyvinyl pyrrolidone (PVP) as a capping agent by a thermal treatment followed by calcination at various temperatures from 673 to 923 K. The structural characteristics of the calcined samples were determined by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and transmission electron microscopy (TEM). A completed crystallization occurred at 823 and 923 K, as shown by the absence of organic absorption bands in the FT‐IR spectrum. Magnetization measurements were obtained at room temperature by using a vibrating sample magnetometer (VSM), which showed that the calcined samples exhibited typical magnetic behaviors.