Cobalt Ferrite Nanoparticles Research Articles

S-scheme CoFe2O4/g-C3N4 nanocomposite with high photocatalytic activity and antibacterial capability under visible light irradiation

Photocatalysts with bactericidal capabilities are taken much more into consideration due to the water disinfection aside from water purification Therefore, a magnetically separable CoFe2O4/g-C3N4 nanocomposite has been synthesized via a simple in-situ chemical method, and its performance in degrading methylene blue (MB), methyl orange (MO), and phenol has been investigated. Multiple characterization techniques were conducted to confirm the successful synthesis of cobalt ferrite (CF), graphitic carbon nitride (CN), and cobalt ferrite/graphitic carbon nitride (CF/CN) nanocomposites. The microscopy images indicated a great reduction in the size of CF nanoparticles in nanocomposites. The magnetic characteristics were studied by a vibrating sample magnetometer (VSM). CF showed a high magnetization value (41.4 emu/g) and by compositing CF with CN, the nanocomposite also showed considerable magnetic properties. Optical properties of the photocatalysts were analyzed and the results denoted that heterostructure formation between CF and CN led to better light absorption, reduction in the band gap energy, and enhancement of charge carriers separation. Among the different synthesized nanocomposites, 400 mg/L of the CF/25 wt% CN nanocomposite showed the best photocatalytic activity in 180 min by degrading 100% of MB. The Mott-Schottky analysis and the results of scavenging experiments divulged the superoxide radicals as the main active species along with proposing a S-scheme mechanism on the degradation pathway for CF/CN nanocomposite. The optimized nanocomposite demonstrated high stability after three cycles by over 98% degradation of MB. Eventually, the antibacterial feature of CF/25CN nanocomposite was assessed against Escherichia coli and Staphylococcus aureus bacteria and resulted in a magnificent performance by reducing 99.9% of both bacteria in 30 min.

Exploring Dielectric and Magnetic Properties of Ni and Co Ferrites through Biopolymer Composite Films

This study explores the synthesis and characterization of chitosan/gelatine films incorporating nickel ferrite (NiFe2O4) and cobalt ferrite (CoFe2O4) nanoparticles. The magnetic nanoparticles exhibit superparamagnetic behaviour, making them attractive for various applications, including biomedical uses. The X-ray diffraction analysis confirmed the successful synthesis of NiFe2O4 and CoFe2O4 nanoparticles, and the scanning electron micrographs illustrated well-dispersed ferrite nanoparticles within the biopolymer network, despite the formation of some aggregates attributed to magnetic interactions. Magnetization loops revealed lower saturation magnetization values for the composites, attributed to the chitosan/gelatine coating and the dielectric studies, indicating increased dielectric losses in the presence of ferrites, particularly pronounced in the case of NiFe2O4, suggesting interactions at the interface region between the polymer and ferrite particles. The AC conductivity shows almost linear frequency dependence, associated with proton polarization and conduction processes, more significant at higher temperatures for samples with ferrite particles.

Green synthesized manganese-doped cobalt ferrite photocatalysts for light driven degradation of dye and optoelectronic studies

Mn-doped cobalt ferrite nanoparticles were synthesized via the green route combustion-assisted method using tamarind seed powder as a fuel with the chemical formula MnxCo1-xFe2O4, where x = 0.0, 0.2, 0.4, and 0.6, and named as CF, MCF-1, MCF-2, and MCF-3 NPs, respectively. XRD, FT-IR, SEM with EDS, XPS, TEM, CV, PL, and UV–visible spectroscopy have been employed to characterize the synthesized nanoparticles. The average crystalline sizes of NPs were 5.7, 6.1, 6.8, and 7.6 nm, and the lattice parameters increases as the manganese dopant level rises, owing to the XRD patterns. FT-IR spectra verified the observation of the metal-oxygen bond's vibrational stretching frequency in the tetrahedral and octahedral lattices. Using X-ray photoelectron spectroscopy, the elemental composition, oxidation state, and transition state of the synthesized nanoparticles were identified. The structure resembles nanoflakes with agglomeration, as revealed by SEM and HRTEM, and the elemental composition was verified by EDS. UV–visible spectroscopy was employed to figure out the bandgap, which decreases as the level of manganese doping rises. As the dose of manganese dopant was increased, the peak intensity of the luminescence spectra reduces. Synthesized NPs showed good electrochemical behaviour in CV studies. Under visible light illumination, the photocatalytic efficacy of synthesized nanoparticles was evaluated with methylene blue dye.

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.

Cobalt Ferrite Nanorods Synthesized with a Facile "Green" Method in a Magnetic Field.

We report a new facile method for the synthesis of prolate cobalt ferrite nanoparticles without additional stabilizers, which involves a co-precipitation reaction of Fe3+ and Co2+ ions in a static magnetic field. The magnetic field is demonstrated to be a key factor for the 1D growth of cobalt ferrite nanocrystals in the synthesis. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy are applied to characterize the morphology and structure of the obtained nanoparticles. According to TEM, they represent nanorods with a mean length of 25 nm and a diameter of 3.4 nm that have a monocrystalline structure with characteristic plane spacing of 2.9 Å. XRD and Raman spectroscopy confirm the spinel CoFe2O4 structure of the nanorods. After aging, the synthesized nanorods exhibit maximum saturation magnetization and coercivity equal to 30 emu/g and 0.3 kOe, respectively. Thus, the suggested method is a simple and "green" way to prepare CoFe2O4 nanorods with high aspect ratios and pronounced magnetic properties, which are important for various practical applications, including biomedicine, energy storage, and the preparation of anisotropic magnetic nanocomposites.

Influence of annealing temperature on microstructure, magnetic and electrical properties of Ce doped cobalt ferrite nanoparticles

Cerium doped cobalt ferrite nanoparticles with chemical formula CoFe1·9Ce0·1O4 were synthesized at different annealing temperatures (600, 700, 800, 900 and 1000C°) via sol-gel auto-combustion method. Thermal analysis for sample annealed at 1000C° was examined through differential scanning calorimetry (DSC) and revealed the presence of exothermic peak at around 500C° attributed to crystallization of prepared nanoferrites. Structural analysis such as phase formation, crystallinity and morphology was investigated by x-ray powder diffraction (XRD) and high resolution transmission electron microscope (HRTEM). XRD study revealed higher dependence of grain size growth with annealing temperatures as compared to lattice parameter. HRTEM investigation confirmed that grains have almost uniform morphology with some agglomeration and confirmed values of lattice parameters and grain sizes calculated from XRD data. Magnetic hysteresis was studied by vibrating sample magnetometer (VSM) at room temperature with an applied field of 20 kOe. The results showed an increase in saturation magnetization and remanent magnetization with increasing of annealing temperature, whereas a decline in coercivity was observed. Distribution of cations at tetrahedral and octahedral sites was investigated using x-ray and magnetic parameters which confirmed the mixed spinel ferrite nature of samples. Dielectric properties were carried out at room temperature in the range 0.1Hz–3.0 MHz. Both dielectric constant and ac conductivity decreased with rising of annealing temperature. Variation of dielectric loss tangent, impedance, electric modulus and relaxation time with temperature were also investigated. The effect of annealing temperature on the structure and its impact on magnetic and dielectric properties has been examined and discussed.

Assessment of chitosan-coated zinc cobalt ferrite nanoparticle as a multifunctional theranostic platform facilitating pH-sensitive drug delivery and OCT image contrast enhancement

Colorectal cancer (CC) is one of the most predominant malignancies in the world, with the current treatment regimen consisting of surgery, radiation therapy, and chemotherapy. Chemotherapeutic drugs, such as 5-fluorouracil (5-FU), have gained popularity as first-line antineoplastic agents against CC but have several drawbacks, including variable absorption through the gastrointestinal tract, inconsistent liver metabolism, short half-life, toxicological reactions in several organ systems, and others. Therefore, herein, we develop chitosan-coated zinc-substituted cobalt ferrite nanoparticles (CZCFNPs) for the pH-sensitive (triggered by chitosan degradation within acidic organelles of cells) and sustained delivery of 5-FU in CC cells in vitro. Additionally, the developed nanoplatform served as an excellent exogenous optical coherence tomography (OCT) contrast agent, enabling a significant improvement in the OCT image contrast in a CC tissue phantom model with a biomimetic microvasculature. Further, this study opens up new possibilities for using OCT for the non-invasive monitoring and/or optimization of magnetic targeting capabilities, as well as real-time tracking of magnetic nanoparticle-based therapeutic platforms for biomedical applications. Overall, the current study demonstrates the development of a CZCFNP-based theranostic platform capable of serving as a reliable drug delivery system as well as a superior OCT exogenous contrast agent for tissue imaging.

Structural, magnetic and dielectric properties of cerium-doped manganese – cobalt ferrite nanoparticles

Co0.50Mn0.50Ce xFe2− xO4 (with x = 0.000, 0.025, 0.050 and 0.100) nanoparticles were synthesised through sol–gel method. The crystallite size and lattice constant are increased from 30 to 50 nm and 8.375 to 8.384 Å, respectively, with increasing Ce content. It was found that Fe3+ cations migrate towards octahedral sites with Ce doping. The optical band gap was decreased from 1.79 to 1.50 eV whereas saturation magnetisation was decreased from 57 to 49 emu/g with increase in Ce substitution. Maximum dielectric constant and minimum dielectric loss, maximum AC conductivity along with moderate magnetic properties were observed for x = 0.050. So, x = 0.050 may be a potential candidate for electromagnetic interference shielding applications.

The relative performance of gelatin hydrogels doped with nanostructured transition-metal ferrites for chromium (VI) removal: Packed bed column studies and insights into reduction mechanisms

The article comprehends investigations using gelatin hydrogels reinforced with cobalt and nickel ferrites to remove chromium ions. The synthesized ferrite nanoparticles are mesoporous with high surface areas of 132.059 m2/g and 141.792 m2/g. The deposition of chromium ions on the dissected surfaces is more evident from the morphological studies. Supporting evidence from thermal studies showed how the nanofiller encapsulation increased hydrogels' thermal stability. The bed capacity in the packed bed column is 32.48 mg/g and 31.81 mg/g for cobalt ferrite and nickel ferrite nanoparticles entrapped hydrogels, respectively. X-ray Photoelectron spectroscopy findings indicated that the presence of characteristic peaks at 578.68 eV and 591.16 eV is assigned to hexavalent chromium, and the peaks observed at 575.56 and 583.71 eV correspond to the trivalent state of chromium. The electron transfer from the iron centre to chromium (VI) favoured the reduction of chromium (VI) to less toxic chromium (III)

Synthesis and influence of Zn substitution on optical and magnetic properties of cobalt ferrite nanoparticles by a polyacrylamide gel route

Synthesis and influence of Zn substitution on optical and magnetic properties of cobalt ferrite nanoparticles by a polyacrylamide gel route

Bentonite as eco-friendly natural mineral support for Pd/CoFe2O4 catalyst applied in toluene diamine synthesis

Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanocomposite (bentonite) surface using a microwave-assisted solvothermal method. The catalyst particles were examined by TEM and X-ray diffraction. The palladium immobilized on the bentonite crystal surface was identified using an XRD and HRTEM device. The obtained catalyst possesses the advantageous property of being easily separable due to its magnetizability on a natural mineral support largely available and obtained through low carbon- and energy footprint methods. The catalyst demonstrated outstanding performance with a 2,4-DNT conversion rate exceeding 99% along with high yields and selectivity towards 2,4-TDA and all of this achieved within a short reaction time. Furthermore, the developed catalyst exhibited excellent stability, attributed to the strong interaction between the catalytically active metal and its support. Even after four cycles of reuse, the catalytic activity remained unaffected and the Pd content of the catalyst did not change, which indicates that the palladium component remained firmly attached to the magnetic support's surface.

Enhancing fermentation yield for biohydrogen production using eco-friendly nickel and cobalt ferrite nanoparticles

AbstractIn recent years, the sustainable metal oxide nanoparticle synthesis using various plant leaf extracts as reducing agents has gained significant attention in the field of renewable energy research. This study explores the biohydrogen yield enhancement potential of two types of nanoparticles derived from olive leaves. Synthesized nanoparticles are characterized by SEM, EDX, and FTIR spectrum analyses; these nanoparticles exhibit mean dimensions of 385 nm and 292 nm. Fermentation experiments were conducted using varying ratios of the two types of nanoparticles ranging from 50 to 500 mg/L to determine the impact of these nanoparticles on bio-hydrogen yield. Remarkably, with the usage of 200 mg/L of nickel ferrite nanoparticles boosted biohydrogen yield by 47%, while 200 mg/L of cobalt ferrite nanoparticles increased it by 41%. These findings highlight the potential of sustainably synthesized nanoparticles, especially those from olive leaves, as catalysts for enhancing biohydrogen production in dark fermentation processes. This research offers promising insights into eco-friendly bioenergy generation.

Photocatalytic degradation of naphthol blue black dye using undoped and Al-doped cobalt ferrite nanoparticles

The current study aims to evaluate the effectiveness of undoped (CoFe2O4) and aluminium-doped cobalt spinel ferrite (CoFe1.1Al0.9O4) nanoparticles as photocatalysts in the process of photocatalytic degradation of organic naphthol blue black (NBB) dye. In the sol-gel auto combustion method, a combination of metal nitrates, citric acid, sodium hydroxide, and liquid ammonia was utilized as the raw chemical ingredients for synthesizing nanoparticles of CoFe2-xAlxO4 (x = 0.0, 0.3, 0.6, 0.9, 1.2, 1.5) spinel ferrites. The nanoparticles were subjected to various characterization techniques including thermal analysis (TGA/DTA), X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and UV–visible spectroscopy for comprehensive analysis. The XRD analysis confirmed the presence of a spinel cubic structure in the synthesized spinel ferrite nanoparticles. The interplanar distance (d) and crystalline size (D) were determined using Bragg's equation and Scherrer's relationship, respectively. The morphological characteristics and elemental composition of the spinel ferrites were confirmed through FE-SEM and EDS. Furthermore, the UV spectrum of the synthesized photocatalyst was investigated to compare the energy band gap between undoped and Al-doped cobalt spinel ferrites. The analysis of photoluminescence (PL) spectra was conducted to investigate the dynamics of charge carriers, focusing on their transfer, relocation, and recombination processes. The surface area of the synthesized photocatalyst ranged from 3.525 to 16.113 m2/g. Photocatalytic degradation of naphthol blue black (NBB) dye was carried out under visible light exposure utilizing both cobalt spinel ferrite nanoparticles without doping and those doped with aluminium. Several factors, including pH level, H2O2 concentration, amount of photocatalyst (spinel ferrite) and initial dye concentration, were considered through the photocatalytic degradation of NBB dye. The highest percentage degradation (%) of NBB dye was determined at pH 11. For NBB dye with an initial concentration of 20 ppm, the maximum degradation was achieved using 200 mg of spinel ferrite nanoparticles per 100 mL dye solution under visible light irradiation for 40 min.

Probing temperature-dependent magnetism in cobalt and zinc ferrites: A study through bulk and atomic-level magnetic measurements for spintronics

Spinel ferrites (MFe2O4) are integral to various industries, particularly spintronics, which utilizes the intrinsic spin of electrons as well as the electronic charge to develop devices that dictate spin-based transport, advancing new memory, logic applications, and improving magnetic storage technologies. These materials are valued for their exceptional optical, magnetic and electrical properties, and their easily tunable shape and size. This flexibility of spinel ferrites and their connection to the material’s magnetic behavior can be investigated by studying a range of spinel ferrite structures. In this study, the magnetic behaviors of cobalt ferrite (CFO) and zinc ferrite (ZFO) nanoparticles were examined using a vibrating sample magnetometer (VSM, bulk magnetometry) and X-ray Magnetic Circular Dichroism (XMCD, atomic magnetometry). The Rietveld refinement of XRD data supported single phase spinel structure, while X-ray Absorption Spectroscopy (XAS), particularly through the Co L-edge XANES analysis, detected both Co2+ and Co3+ ions in CFO, suggesting significant ferromagnetic behavior due to octahedral site occupation. In contrast, ZFO exhibited antiferromagnetic character, with Zn2+ ions in tetrahedral sites, and canted antiferromagnetism manifesting as a hysteresis loop below 300 K, potentially related to lattice distortions or strain. At the atomic scale, XMCD analysis, along with sum rules, estimated the average magnetic moments for cobalt and zinc ferrites to be 3.045 ± 0.1 (1.448 ± 0.1) and 0.657 ± 0.1 (2.12 ± 0.1) μB at temperatures of 300 K (90 K), respectively. However, VSM-based bulk measurements indicated magnetic moments of 2.566 (2.288) and 0.281 × 10−3 (0.6503 × 10−3) μB for CFO and ZFO, respectively, at the same temperatures. The observed variation between bulk and atomic-scale magnetic moments points to complex interstitial interactions within the spinel ferrite’s sublattices. This discrepancy between the atomic-scale and bulk magnetic moments suggests intricate interstitial interactions within the spinel ferrite’s sublattices. These insights into the structural and magnetic intricacies of spinel ferrite nanoparticles enhance our understanding, facilitating the design of cutting-edge spintronic devices.

The effect of apple pectin agent on the structural, magnetic, and optical properties of cobalt ferrite nanoparticles synthesized by the auto-combustion sol-gel method

In this investigation, in order to enhance the properties of cobalt ferrite magnetic nanoparticles, apple pectin was utilized as a natural additive during the sol-gel auto-combustion technique. Differential thermal analysis (DTA) and thermogravimetric (TGA) curves revealed that the initial temperature of the combustion process drops when apple pectin is present, indicating that this additive improves combustion conditions. The X-ray diffraction (XRD) patterns demonstrated that a cubic spinel structure of pure cobalt ferrite nanoparticles was formed in the presence of apple pectin without the existence of a secondary phase. Additionally, the structural parameters, including the lattice parameters, average crystallite size, and cation distribution between the tetrahedral and octahedral sites, were determined using the Rietveld refinement method. All the synthesized samples exhibited a mixed spinel structure based on the investigation of the cation distribution. A decrease in particle size and nanoparticle agglomeration was observed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Moreover, the magnetic properties were investigated. According to the experimental findings, the presence of 0.3 g apple pectin increased the saturation/remanence magnetization and coercivity of cobalt ferrite nanoparticles. The improvement in magnetic properties was correlated with the average crystallite size, cation distribution, and magnetic moment of the cations occupying the octahedral/tetrahedral sites. In addition, the diffuse reflectance spectroscopy (UV–Vis-DRS) results showed that the energy of the band gap varies from 1.54 to 2.21 eV in the synthesized samples.

Green Synthesis for Fabrication of Cobalt Ferrite Nanoparticles with Photocatalytic Dye Degrading Potential as a Sustainable Effluent Treatment Strategy

Green Synthesis for Fabrication of Cobalt Ferrite Nanoparticles with Photocatalytic Dye Degrading Potential as a Sustainable Effluent Treatment Strategy

Heat transfer characteristics of cobalt ferrite nanoparticles scattered in sodium alginate-based non-Newtonian nanofluid over a stretching/shrinking horizontal plane surface

Abstract Magnetite and cobalt ferrite (CoFe2O4) nanoparticles are frequently utilized in several applications, including magnetic drug delivery, hyperthermia, magnetic resonance imaging, etc. In the current investigation, the magnetohydrodynamic three-dimensional heat transfer (HT) flow induced by a non-Newtonian Eyring–Powell fluid is incorporated by a carrier sodium alginate (NAC6H7O6)-based CoFe2O4 nanoparticles over a deformable (stretching/shrinking) horizontal plane surface with orthogonal shear stress and power-law velocity. The HT analysis along with the substantial effect of irregular heat source/sink as well as entropy generation is also performed. The similarity variables altered the posited leading equations into ordinary differential (similarity) equations. The function bvp4c in Matlab is then used to solve these equations numerically for various parameter values. Results indicate that, in general, there are two alternative solutions for the phenomenon of suction and deformable parameters. In addition, the essential thermal evaluation is enhanced owing to the significance of CoFe2O4 nanoparticles, magnetic parameter, and irregular heat source/sink.

Impact of CoFe2O4 Magnetic Nanoparticles on the Physical and Mechanical Properties and Shape Memory Effect of Polylactide

The acceleration in advancements of smart materials and non-contact controlled devices in the field of 4D printing is facilitated by the use of magnetically responsive shape memory polymer (SMP) composites. This study is dedicated to the development of promising shape memory materials based on polylactic acid (PLA) and cobalt ferrite (CoFe2O4) nanoparticles. The activation of the shape memory effect (SME) in magnetic nanoparticle composites was achieved by applying a high-frequency alternating magnetic field (HFAMF). The PLA/CoFe2O4 composites exhibited a remarkable shape recovery ratio (>84%) and underwent rapid heating when exposed to HFAMF. The interaction of these composites with mouse adipose-derived mesenchymal stem cells demonstrated adequate cytocompatibility. The rapid magnetosensitive behavior and high shape recovery characteristics of PLA/CoFe2O4 composites make them promising candidates for biomedical applications.

The Role of Cobalt Ferrites Nanoparticles on Structural and Electrochemical Properties of Mesoporous Silica for Supercapacitor Applications

The Role of Cobalt Ferrites Nanoparticles on Structural and Electrochemical Properties of Mesoporous Silica for Supercapacitor Applications

Characterization of Thermally Stable Bamboo Fiber Sheet Loaded with Cobalt Ferrite Nanoparticles

Characterization of Thermally Stable Bamboo Fiber Sheet Loaded with Cobalt Ferrite Nanoparticles