Synthesis Of Cobalt Ferrite Nanoparticles Research Articles

Preparation and study of the effect of pH value on structural, morphological, electrical and magnetic properties of CoFe2O4 nanoparticles prepared by sol-gel precipitation method

The present study reports the synthesis of cobalt ferrite nanoparticles (CoFe2O4 NPs) using the sol-gel precipitation process via mixing a stoichiometric ratio of cobalt chloride (1 M) and ferric chloride (2 M). The molar of ferric to cobalt was mentioned (2:1) and then 2 M of sodium hydroxide was added. The structural and morphological features of the material were assessed using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and atomic force microscopy (AFM). The electrical properties were analyzed using an LCR meter, while the magnetic properties were measured using a vibrating sample magnetometer (VSM). Fourier-transform infrared spectroscopy (FTIR) investigated the material's molecular vibrations. The X-ray diffraction (XRD) analysis revealed that all the samples exhibited a cubic spinal structure, and no additional peak was detected. Interestingly, the average size of the crystallites (D) decreased from 17.74 nm to 16.58 nm as the pH level increased from 7 to 13. This finding provides important insights into the behaviour of the tested samples under different pH conditions. The formation of the ferrite spine was confirmed by FTIR spectroscopy, with the primary detected bands (408.92–470.65 cm−1) attributed to the octahedral complexes and (516.94–588.31 cm−1) assigned to the tetrahedral ones. The dielectric and imaginary part of the dielectric constant decreased with increasing pH values excluding samples prepared at pH = 11. All samples with different pH values exhibit resonance peaks at frequencies up to (1 KHz). The magnetic measurements carried out by the VSM instrument, the result show that the saturation magnetization increases with increasing pH and the higher saturation magnetization is 68 emu. g1.

Anti-Proliferative Activity of Poloxamer Cobalt Ferrite Nanoparticles against Human Prostate Cancer (DU-145) Cells: In-Vitro Study

Prostate cancer is the second most frequent type of cancer death in men. This study refers to the novel hyperthermia application of poloxamer-coated cobalt ferrite as a new approach for thermal eradication of DU-145 human prostate cancerous cells under a radio frequency magnetic field (RF-MF). The hydrothermal method was applied for the synthesis of cobalt ferrite nanoparticles. Then, the structure, size, and morphology of nanoparticle were characterized. The cytotoxicity of the synthesized nanoparticles and RF-MF exposure on DU-145 prostate cancer cells was investigated separately or in combination with colony formation methods and MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] assay. Transmission electron microscopy (TEM) confirmed the spherical morphology of nanoparticles with a size of 5.5 ± 2.6 nm. The temperature of cells treated with nanoparticles under RF-MF reached 42.73 ± 0.2°C after 15 min. RF-MF treatment or nanoparticles have not affected cell viability significantly. However, the combination of them eradicated 53% ± 4% of cancerous cells. In-vitro hyperthermia was performed on human prostate cancer cells (DU-145) with cobalt ferrite nanoparticles at specific concentrations that demonstrated a decrease in survival fraction based on colony formation assay compared to cells that were treated alone with nanoparticles or with RF-MF.

A simple microwave-assisted synthesis of cobalt ferrite nanoparticles and its application for the determination of lead ions in rooibos (Aspalathus linearis) tea.

In this study, a magnetic sorbent assisted dispersive solid phase extraction (DSPE) method was used to preconcentrate lead ions from rooibos tea samples for determination by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS). Cobalt ferrite magnetic nanoparticles (CoFe2O4 MNPs) were synthesized by microwave assisted digestion. Limits of detection and quantification were calculated as 5.3 and 17.6µg/L, respectively, in a linear dynamic range of 20-800µg/L. The enhancement factor of the developed method was found to be 80-folds when compared to the detection limit of the regular FAAS system. The percent recoveries obtained for rooibos tea samples spiked at different concentrations were in the range of 77 - 125%, with high repeatability as indicated by low standard deviations. The findings of the study demonstrated that the CoFe2O4 MNPs-based extraction method is a straightforward, fast, affordable, safe, and eco-friendly approach to qualifying/quantifying lead with high precision in the selected beverage sample.

Enhanced visible light-driven photocatalytic activity of green synthesized cobalt ferrite nanoparticles

Cobalt ferrite nanoparticles were synthesized through green synthesis using Erythrina variegata leaf extract. The presence of phytonutrients in the Erythrina variegata leaf extract was confirmed by phytonutrient screening analysis. The thermal, structural, optical, functional, chemical, morphological, and compositional properties of prepared nanoparticles were analysed. The crystal violet (CV) and congo red (CR) dyes eliminated from water using CoFe2O4 NPs as an adsorbent, has been reported. The thermal stability of as-prepared samples was studied by TG-DTA and powder XRD analysis exhibits a cubic inverse spinel structure. By using UV–Vis spectroscopy, the lower band gap energy of CoFe2O4 NPs was found to be around 1.86 eV. The relevant FTIR and Raman spectra indicated Fe–O (tetrahedral site) and Co–O (Octahedral site) band, which attributed to the stretching vibration modes. The cubic-shaped and irregular agglomerated particles was examined from SEM images. The existence of all required elements in prepared CoFe2O4 NPs were confirmed by EDX and XPS analysis. Leaching experiment using the seed germination method for CoFe2O4 catalyst was evaluated. Moreover, the effective photocatalytic performance of crystal violet (CV) and congo red (CR) dye adsorption using CoFe2O4 catalyst within 120 min on the effect of pH, dye dosage, exposure time, and kinetic studies under visible light were investigated. The maximum dye removal efficiency of 85.18 % and 79.58 % was observed using 25 mg/L at pH 9 for CV and CR dyes, respectively. Trapping experiments revealed that O2•− is the major active species in the dye degradation. Recycling experiments revealed good stability after three cycles for CoFe2O4 catalyst. As a result, the prepared CoFe2O4 NPs can be utilized as an effective adsorbent for wastewater treatment.

Influence of orange residue content on Sol-gel synthesis of cobalt ferrite Nanoparticles: Morphological and magnetic properties

Cobalt ferrite was successfully produced from nitrates using, as a precursor, 20, 40 or 60 g.L-1 of orange residue in water, followed by calcination at 973, 1073, or 1173 K for 6 h. Fourier transform infrared spectroscopy indicates that the increase in carbonyl-related peak content in the precursor bath due to a higher concentration of orange particulate favors the reaction of nanocrystals' formation. Rietveld's analysis of x-ray diffraction data indicates that the percentage of cobalt ferrite tends to increase with the concentration of orange residue, whereas grain size increases with calcination temperature. The concentration of cobalt ferrite is 99% for samples produced with 60 g.L-1 of orange particulate, a novel achievement for green synthesis using an industrial residue as a precursor. Magnetic anisotropy, obtained from ferromagnetic resonance measurements, scales with the crystalline grains' size, being dependent on calcination temperature, regardless of orange particulate precursor concentration.

Synthesis of intrinsic, Manganese and magnesium doped cobalt ferrite nanoparticles: Physical properties for antibacterial activities

The work emplaced in this research is the synthesis of cobalt ferrite nanoparticles (CFNPs) doped with manganese and magnesium for antibacterial activities by sol-gel protocol. The physicochemical properties of CFNPs, Mg_CFNPs and Mn_CFNPs as described by the characterization techniques shows good results. Cubic spinel structures of CFNPs, Mg_CFNPs and Mn_CFNPs were observed by the X-ray diffraction (XRD) technique. The transmission electron microscope (TEM) established the spherical shape of the samples. The functional groups embedded in the sample were observed using FTIR and complimented by the Raman analysis. The formulated sample was used against four pathogenic strains S. epidermidis; B. subtilis; E. coli and K. pneumoniae. Higher susceptibility against E. coli was observed with Mg_CFNPs compared to the pristine (CFNPs) and Mn_CFNPs. Hence, the formulated Mg_CFNPs are highly significant and propitious for antibacterial activities.

Green Synthesis of Cobalt Ferrite Nanoparticles: An Emerging Material for Environmental and Biomedical Applications

Research and utilization of nanotechnology are growing exponentially in every aspect of life. The constant growth of applications for magnetic nanoparticles, specifically nanoferrites, attracted many researchers. Among them, nanocobalt ferrite is the most crucial and studied magnetic nanoparticle. Environmentally benign synthetic methods became necessary to minimize environmental and occupational hazards. Green synthesis approaches in science and technology are now widely applied in the synthesis of nanomaterials. Herein, we reviewed recent advances in synthesizing nanocobalt ferrites and their composites using various scientific search engines. Subsequently, various applications were discussed, such as environmental (treatment of water/wastewater, photocatalytic degradation of dyes, and nanosorbent for environmental remediation) and biomedical (nanobiosensors for cancer diagnosis at the primary stage, effective targeted drug delivery, magnetic resonance imaging, hyperthermia, and potential drug candidates against cancer and microbial infections). This review offers comprehensive knowledge on how to choose appropriate natural resources for the green synthesis of nanocobalt ferrite and the benefits of this approach compared to conventional methods.

Enhancement of specific surface area of CoFe2O4 powders synthesized by KCl-assisted solution combustion: effect of KCl content and initial pH

In the present study, the potassium chloride-assisted solution combustion method was used to synthesize cobalt ferrite nanoparticles. Potassium chloride salt was used as a specific surface enhancer and nitric acid was used as an auxiliary oxidizer and pH regulator. The simultaneous effect of the initial pH of the solution and the amount of added potassium chloride salt on the specific surface area, structural, microstructural and magnetic properties of synthetic powders were studied. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FT-IR), Vibrating Sample Magnetometer (VSM) at room temperature and Brunnauer–Emmet–Teller (BET) method were used for those purposes. The results showed that the initial pH and the amount of potassium chloride salt had an interaction effect on the specific surface area of cobalt ferrite powders. Under optimal conditions, cobalt ferrite powders with high specific surface area of 87.77 m2g-1 were successfully synthesized. Synthetic powders had mesoporous microstructure and hard magnetic behavior.

Precipitating agent (NaOH and NH4OH) dependent magnetic properties of cobalt ferrite nanoparticles

This work investigates the effect of precipitating agents sodium hydroxide (NaOH) and ammonium hydroxide (NH4OH) on the structural and magnetic properties of cobalt ferrite nanoparticles. The co-precipitation method was used to synthesize cobalt ferrite nanoparticles (S1 and S2). The synthesized nanoparticles were characterized by techniques such as x-ray diffraction (XRD) and scanning electron microscopy (SEM) and using a vibrating sample magnetometer at temperatures of 10 and 300 K. XRD results confirm the formation of cobalt ferrite nanoparticles. SEM images revealed the formation of round-shaped particles with a diameter range of 10–20 nm. Crystallite size, saturation magnetization, coercivity, squareness ratio, and anisotropy constant depend on the precipitating agents. The values of saturation magnetization for S1 are 23.6 and 32.6 emu/g whereas those for S2 are 27.4 and 41.2 emu/g at 10 and 300 K, respectively. These nanoparticles can be explored for applications in the fields of magnetism and biomedical science.

Cost-Effective Synthesis of Cobalt Ferrite Nanoparticles by Sol-Gel Technique

In material science, doping method is employed to produce nanoferrites with desired characteristics. Recently, cobalt doped iron oxide nanomaterials have gained importance in industry for multiple electronic/electrical applications. Large number of methods have been adopted for the synthesis of nanoparticles (NPs), but high manufacturing cost, uniform sized, and anisotropic behaviors limit the commercial applications. In the presented work, cobalt doped (Co-Fe nanomaterials) are developed by a cost-effective sol-gel approach. The doped cobalt ferrites NPs (1%, 2%, and 3% doping of cobalt) were prepared and characterized by XRD, SEM & TEM, FTIR, and VSM techniques. XRD and microscopic (SEM & TEM) analysis revealed synthesis of hexagonal structured cobalt ferrite sized from ~16nm to ~8nm, with the increasing doping pattern of Cobalt from 1% to 3%. FTIR analysis showed the formation of well-structured oxides, which is in strong agreement with XRD and microscopy techniques. Moreover, VSM analysis revealed that cobalt ferrite nanoparticles possess ferromagnetic properties with Ms, Mr and Hc values of 0.038emu/g, 0.005emu/g and 405.19Oe respectively. In addition, squareness (Mr/Ms = 0.16) indicates the presence of single domain spherical particles.

Investigation of antibacterial, antioxidant, and anticancer properties of hydrothermally synthesized cobalt ferrite nanoparticles

Investigation of antibacterial, antioxidant, and anticancer properties of hydrothermally synthesized cobalt ferrite nanoparticles

Influence of Orange Residue Content on Sol-Gel Synthesis of Cobalt Ferrite Nanoparticles: Morphological and Magnetic Properties

Influence of Orange Residue Content on Sol-Gel Synthesis of Cobalt Ferrite Nanoparticles: Morphological and Magnetic Properties

Accurate band gap determination of chemically synthesized cobalt ferrite nanoparticles using diffuse reflectance spectroscopy

Optical band gap of cuboidal Cobalt ferrite (CoF) Nanoparticles (NP), synthesized using wet chemical method, was accurately determined, by combining Diffuse Reflectance Spectroscopy (DRS) of the nanopowder, Schuster-Kubelka-Munk (SKM) formalism and the application of a detailed band gap estimation algorithm, using which absorption onsets and corresponding base line segments from the Tauc plots were precisely identified. Structural and compositional characterizations such as XRD, FE-SEM, TEM and EDX, were used to conclude that the NP exhibited cubic crystal structure with an average crystallite size of 14 nm. The values of indirect and direct band gaps were calculated to be 0.79 ± 0.01 eV and 1.5 ± 0.01 eV, respectively. The band gap shift for the nanocrystallites, from the bulk band gap, estimated using the effective mass model, came up to a value of 0.084 eV, which corresponded well to the experimentally obtained direct band gap of CoF NP. The direct and indirect band gap values were found to be well consistent with the partially inverse spinel crystal structure of the NP, emphasized using magnetization measurement.

Synthesis of cobalt ferrite nanoparticles from waste iron ore tailings and spent lithium ion batteries for photo/sono-catalytic degradation of Congo red

Cobalt ferrite nanoparticles were successfully synthesized by a combined coprecipitation method using recovered iron and cobalt from waste iron ore tailing and spent lithium ion batteries, respectively, characterized and utilized for photo/sono-catalytic degradation of Congo red. Characterizations by powder XRD, UV-DRS, SEM/TEM and surface area measurement revealed the formation of single phase spinel-type structure with average size 40–50 nm, surface area (36.2 m2/g), saturation magnetization (63 emu/g) and band gap energy (1.61 eV). XPS results showed that iron and cobalt in CoFe2O4 are present as Fe3+ and Co2+. It efficiently degraded CR dye under visible light and ultrasonic power for which the most probable degradation pathways were proposed. Recyclability tests showed the magnetic catalyst is reasonably stable, efficient and easily separated using an external magnet. Moreover, the present work gives further insight towards possible use of solid wastes in synthesis of value added materials in large scale for environmental applications.

The effects of fuel type onto the structural, morphological, magnetic and photocatalytic properties of nanoparticles in the synthesis of cobalt ferrite nanoparticles with microwave assisted combustion method

In this experimental study, the synthesis of cobalt ferrite nanoparticles, one of the most important types of ferromagnetic spinel ferrite materials was realized by using a method known as microwave assisted combustion method. The effects of the substance used as fuel on the structural, morphological, magnetic and photocatalytic properties of synthesized nanoparticles were investigated. Firstly, samples were prepared using urea, glycine and citric acid as fuel and then the samples were comprehensively characterized by advanced analysis techniques such as XRD, FT-IR, TEM, SEM, VSM, BET. Moreover, the usability of the obtained nanoparticles in photocatalytic degradation process of Procion Yellow H-E3G textile dye as photocatalyst was investigated. The results obtained indicate that the fuel used is highly effective on various properties of the synthesized materials. From the experiments performed to evaluate the photocatalytic performances of the nanoparticles, it was observed that each of the three different fuel matters used for the synthesis of nanoparticles were highly effective on the photocatalytic degradation of the organic pollutant. Furthermore, almost all the dye content in solution was completely removed at the end of the experimental period which lasted for 90 min.

Synthesis of water dispersible phosphate capped CoFe2O4 nanoparticles and its applications in efficient organic dye removal

We synthesize cobalt ferrite nanoparticles capped with an ultrathin phosphate layer of ∼ 1 nm thick by co-precipitation followed by hetero condensation of free surface OH- groups of orthophosphoric acid on CoFe2O4 particles. The synthesized phosphate capped CoFe2O4 nanoparticles (CFP) are characterized using X-ray diffractometer (XRD), simultaneous thermogravimetric analyser with differential scanning calorimetry, Fourier transform infrared spectroscopy (FTIR), Vibrating sample magnetometer, Dynamic light scattering, Transmission electron microscopy and Energy dispersive X ray spectroscopy. XRD results confirm the formation of CoFe2O4 nanoparticles and the signature of POM stretching vibrations at 900 – 1200 cm−1 seen in FTIR spectrum confirm the surface bound phosphate moieties. The prevalent adsorption of water molecules through hydrogen bonding with PO43- moieties capped on CoFe2O4 nanoparticles made them hydrophilic in nature. The adsorption of different dyes on these particles is studied systematically. The phosphate moieties over cobalt ferrite greatly enhanced the adsorption of methylene blue where the adsorption efficiency and adsorption capacity were ∼ 89.5 % and ∼ 4.5 mg. g−1 respectively within 5 min. of incubation, as compared to nearly zero adsorption of methylene blue on uncoated CoFe2O4. On the other hand, the adsorption efficiency and capacity of brilliant blue R, bromo phenol blue and rhodamine B on CFP was very low. These results show that the adsorption of dye molecules over these particles depends on the nature of interactions between their functional moieties. The modes of interaction and influence of different functional moieties of dyes with phosphate moieties on CFP is studied and compared. As compared to the nonmagnetic nanoparticle based dye removal, the present approach is most suited for straight through channel dye removal without labor intensive steps such as centrifugation, precipitation and filtration.

Low temperature synthesis and investigations of magnetic properties of cobalt ferrite nanoparticles

In the present study we report the synthesis of cobalt ferrite nanoparticles using one of the well-known wet chemical method i.e. sol-gel auto combustion technique. The synthesis was carried out at sufficiently low temperature of 100°C. Citric acid was used as a fuel in the synthesis process. The obtained nanoparticles were sintered at 550°C for 4 h and then used for structural and magnetic investigations. The phase pure nature and nano crystalline nature was investigated through X-ray diffraction technique. Room temperature X-ray diffraction pattern show well defined reflections oriented at different Bragg’s angle corresponding to Miller indices (220), (311), (222), (400), (422), (511) and (440). All this reflections belongs to cubic spinel structure. Thus, XRD analysis confirms the formation of single phase compound. The particle size was obtained through Scherrer’s equation and found to be 21 nm, indicating the nanocrystalline nature. The magnetic properties were investigated using pulse field hysteresis loop tracer at room temperature. The saturation magnetization show increased values as compared to the bulk cobalt ferrite. The coercivity found to be less which exhibits the superparamagnetic behaviour. The obtained structural and magnetic parameters are useful in biomedical applications.

A facile approach to synthesis of cobalt ferrite nanoparticles with a uniform ultrathin layer of silicon carbide for organic dye removal

Dispersions of surface capped ferrite nanoparticles have many practical applications in heat transfer, optics, memory devices, sensors and biomedicine. However, capping of ferrite nanoparticles with a stable ultrathin layer of organic or inorganic materials, without compromising magnetic properties, still remains a challenge. Here, we demonstrate, for the first time, a facile and rapid approach to cap cobalt ferrite nanoparticles with a uniform ultrathin layer of silicon carbide (~1.4 nm) by using an organosilica coating agent, dichlorodimethylsilane (DCDMSi), through sonochemical approach. The ultrasonic cavitation process is exploited for aiding the rapid and effective capping of SiC over CoFe2O4 through self-restrained condensation of silanol moieties. The synthesized silicon carbide coated CoFe2O4 nanoparticles (CFSi) and uncoated CoFe2O4 (CFUC) are characterized using Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analyzer with simultaneous differential scanning calorimetry (TGA-DSC), Vibrating sample magnetometer (VSM), X-ray diffractometer (XRD), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX) and dynamic light scattering (DLS). The organic dye adsorption ability of capped particles was investigated using dyes with different functional moieties. The plausible mechanism of SiC capping, adsorption mechanism and the mode of interaction of different functional moieties are also elicited. The unique benefits of this approach include non-requirement of metal catalysts, hazardous chemicals, high temperature or pressure, long reaction time and exogenous initiators. Unlike the conventional approaches, this technique facilitates synthesis of fine magnetic nanoparticles with a uniform and robust ultrathin layer of silicon carbide. The results suggest that straight through channel dye removal by continuous feed through packed beds of CFSi particles under a magnetic field is possible without the need of centrifugation, precipitation, filtration, washing and ultrasonication.

Surfactant based synthesis and magnetic studies of cobalt ferrite

Nanoparticles of cobalt ferrite were synthesized by two different surfactants cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) by the microemulsion method. Formation of cobalt ferrite was confirmed by structural characterization techniques XRD and TEM. The magnetic properties of these systems were studied using Mossbauer spectroscopy and SQUID magnetometry. The study determined the impact of the synthetic procedure and surfactant composition on the nanomaterial characteristics. The overall magnetic response for the material was different compared to the bulk with a major decrease in room temperature magnetic saturation. Magnetic properties were affected by the type of surfactant template due to its impact on the geometry of the synthesized cobalt ferrite nanoparticles.

Synthesis of cobalt ferrite nanoparticles with different morphologies via thermal decomposition approach and studies on their magnetic properties

Abstract CoFe2O4 nanoparticles have received immense attention in recent times due to their interesting magnetic properties and they possess good thermal and chemical stability. In the present study, CoFe2O4 nanoparticles have been synthesized via a novel thermal decomposition approach using Co–Fe glycolate precursors. The Co–Fe glycolates were prepared by refluxing the corresponding metal salts in ethylene glycol. The morphology of CoFe2O4 nanoparticles can be tailored by varying the synthesis temperature of Co–Fe glycolates and also the amount of ethylene glycol used. The morphology of CoFe2O4 changes from nanorods to hexagonal particles on changing the synthesis temperature of Co–Fe glycolates from 160 °C to 220 °C, On the other hand, on increasing the amount of ethylene glycol while keeping the synthesis temperature constant (220 °C), the morphology of CoFe2O4 nanoparticles changes from hexagons to octahedra. The Co–Fe glycolates and the CoFe2O4 nanoparticles were characterized using several analytical techniques. The magnetic properties of CoFe2O4 nanoparticles were studied by vibrating sample magnetometry. The CoFe2O4 nanoparticles exhibit high coercivity at 5 K with moderate saturation magnetization.