CoFe2O4 Magnetic Nanoparticles Research Articles

Unlocking the magnetic potential of Fe2O3 nanoparticles by single-step synthesis of cobalt-infused nanomaterials for chromium removal

The study optimized the chromium removal capacity of Fe2O3 nanoparticles through the infusion of cobalt using a single-step synthesis method. This approach not only enhanced their magnetic properties but also employs less-chemical synthesis techniques, ultimately yielding highly magnetic CoFe2O4 nanoparticles and less impurities. The prepared materials underwent comprehensive testing, encompassing examinations of their optical properties, structure, chemical composition, and surface characteristics using various analyticals methods. In a span of 90 min under visible light exposure, CoFe2O4 nanoparticles exhibit the ability to remove more that 90% of chromium. This was corroborated through analysis using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). Moreover, the study illustrates that increased temperatures amplify the endothermic process of chromium adsorption. Positive ΔH°, negative ΔS°, and heightened Cr(IV) adsorption are linked to the temperature effects on solubility, mobility, and dissolved oxygen. Both Langmuir (R2 = 0.95, RL = 0.055) and Freundlich models (R2 = 0.98, n = 0.69) suggest favorable adsorption. The efficient Cr(IV) adsorption by CoFe2O4 nanocomposite is attributed to a rapid reaction rate and substantial capacity, following pseudo-second order kinetics (rate constant 0.01 g mg−1 min−1, R2 = 0.99).Graphical abstract

Treatment of pharmaceutical wastewater by a sequential KMnO4/CoFe2O4-mediated catalytic ozonation process

Pharmaceutical compounds, which are of utmost concern, have found their way into natural water bodies, causing numerous problems for both human health and ecosystems. In this study, an integrated system including potassium permanganate (PM) pre-oxidation, followed by a heterogeneous catalytic ozonation process (HCOP) using CoFe2O4 magnetic nanoparticles (CF MNPs), and an activated sludge-based biological treatment (BT) was employed for the first time to treat pharmaceutical wastewater (PWW). In this regard, the effluent from PM pre-oxidation process was used as a batch for the HCOP, and the effluent was used as a batch for the BT process. The results showed that PM pre-treatment of PWW (PM dose = 1264 mg/L and pH = 8.0) reduced the COD content of the PWW from 900 ± 50 to 443 ± 10 mg/L within 120 min of reaction time. The application of HCOP for further treatment of PWW dramatically enhanced COD and TOC removal compared with the single ozonation process (SOP). Under optimum conditions (pH = 10, O3 = 4.0 mg/L, and CF MNPs = 1000 mg/L), HCOP successfully reduced the COD and TOC contents of PWW by 37 % and 46.1 %, respectively, after 120 min of treatment. The consecutive combination of PM pre-treatment followed by HCOP exhibited good potential and reduced COD by over 69 %, resulting in a residual COD of less than 280 mg/L. A biodegradability ratio of over 81 % and residual COD of 54 mg/L for the PWW treated by the PM/HCOP/BT integrated system indicated that biodegradability was enhanced, and a high fraction of refractory organic compounds was effectively removed. In conclusion, the PM/HCOP/BT integrated system is an efficient, synergistic, and easy-to-operate technique for enhancing the biodegradability of PWW.

Synthesis of Cobalt Ferrite Nanocomposite Coated with Aluminum Oxide and Application in Protein Removal Process in Natural Rubber

Proteins in latex are the main cause of unwanted effects for users, such as skin allergies and unpleasant odors. Therefore, it is necessary to remove protein from rubber latex before putting it into production. The study presents a method and process for synthesizing CoFe2O4 (CFO) magnetic nanoparticles coated on the surface with an Al2O3 coating. Then, based on the surface adsorption mechanism of the Al2O3 coating, the protein in the latex is adsorbed and recovered from the solution by the magnetism of the CFO magnetic core. The CFO material synthesized by the co-precipitation method has an evenly distributed spherical shape, size 27.3 nm, from a saturation of 53.9 emu/g. The synthesized CFO@Al2O3 has an evenly distributed spherical shape, size 56.2 nm, from a saturation of 39.07 emu/g, and a surface area of 216.75 m2/g. The CFO@Al2O3 nanoparticles have the ability to separate proteins up to 96.71% and have been researched and proven by the Kjeldahl method.

Highly efficient remediation of chlorpyrifos and malachite green by an SBA-15 incorporated guar gum-grafted-poly (acrylic acid)/cobalt ferrite matrix for water purification

The Santa Barbara Amorphous-15-guar gum-grafted-poly (acrylic acid)/cobalt ferrite (SBA-15-GG-g-PAA/CoFe2O4) mesoporous adsorbent was prepared by graft copolymerization of acrylic acid (AA) onto guar gum (GG) in the Santa Barbara Amorphous-15 (SBA-15) substrate presence, followed by incorporating CoFe2O4 magnetic nanoparticles (MNPs). Diverse analyses were conducted to identify the prepared mesoporous adsorbent’s chemical and morphological properties, thermal resistance, magnetic characteristics, surface area, and porosity. Based on the magnetic hysteresis loops, the mesoporous adsorbent rendered ferromagnetic behavior. According to TGA, it has char yields of 72 wt% at 800 °C and superparamagnetic behavior (Ms of 3.22 emu.g−1). The crystalline structure and cubic phases of CoFe2O4 MNPs in the GG-g-PAA amorphous matrix were demonstrated by XRD. The CoFe2O4 MNP formation with partial aggregations onto smooth, nonporous, and regular surfaces of the GG was depicted by FESEM images. Also, the precisely-arranged hexagonal structure with cylindrical pores of SBA-15 was authenticated by FESEM images. Additionally, the SBA-15 substrate has increased the BET surface area of the prepared mesoporous adsorbent to 40.55 m2/g, which is higher than the composite without SBA-15 mesoporous silica. Several experimental setups were used to evaluate the effectiveness of adsorption, including pH of the medium (4–9), Adsorbent dosage (0.003–0.02 g), Interaction time (1–25 min), and Initial pollutant concentration (50–400 mg/L). Using 0.003 g of mesoporous adsorbent at 25 °C, chlorpyrifos (CPF) and malachite green (MG) had maximum adsorption capacities (Qmax) of 909.1 mg/g and 1000.0 mg/g, respectively. In this study, the Langmuir isotherm model fitted the adsorption data perfectly withRMG2 = 0.9987 andRCPF2 = 0.9994, and the pseudo-second-order model explained the adsorption kinetics with RMG2 = 0.9644 and RCPF2 = 0.9923. MG and CPF adsorption to the SBA-15-GG-g-PAA/CoFe2O4 mesoporous adsorbent was successful due to hydrogen bonds, exchange interactions, diffusion, and entrapment in the hydrogel network. In addition to the three-dimensional structure, the mesoporous adsorbent has available adsorption sites for reactive molecules. The reusability of the SBA-15-GG-g-PAA/CoFe2O4 was perused and showed that the mesoporous adsorbent can be separated efficiently and retrieved in three sequential cycles without considerable diminution in the adsorption efficiency.

MXene/BC@CoFe2O4 aerogel with excellent electromagnetic interference shielding and enhanced mechanical property

As electromagnetic radiation gradually increases, electromagnetic shielding becomes increasingly crucial. In the field of electromagnetic interference shielding, MXene aerogels have gradually attracted attention. However, the applicability of MXene aerogels is limited due to their poor mechanical and electromagnetic shielding capabilities. To address these issues, a hybrid aerogel, MXene/BC@CoFe2O4, was created using in-situ growth and single-directional freeze-drying methods. By generating CoFe2O4 magnetic nanoparticles on the surface of BC and using BCFO composite cellulose to modulate the electromagnetic interference shielding effectiveness (EMI SE) of MXene aerogel, the EMI SE of MXene/BC@CoFe2O4 aerogel reached 82.5 dB. In comparison to MXene aerogel, the compressive stress of MBCA is increased by 3.6 times, and BC@CoFe2O4 composite cellulose also improves the mechanical properties of MXene aerogel. The synthesized MXene/BC@CoFe2O4 aerogel demonstrates outstanding electromagnetic shielding performance and enhanced mechanical properties, presenting significant potential applications in aerospace and electrical equipment industries.

Synthesis and application of CoFe₂O₄@THAM@PHG‐SO₃H nanoparticles as a new and highly recyclable nanocatalyst in the one‐pot multicomponent synthesis of 3,4‐dihydropyranochromenes and chromeno[3,4‐b]quinoline‐6‐ones

In this study, we have developed a new environmentally‐friendly magnetic nanocatalyst by treating CoFe₂O₄ magnetic nanoparticles with chlorosulfonic acid, tris(hydroxymethyl)aminomethane (THAM), 1,2‐dichloroethane, and phloroglucinol (PHG). They confirmed the synthesis of the catalyst using various techniques such as FT‐IR, SEM, MAP, EDS, XRD, TGA, DTA, and VSM. The researchers then evaluated the catalytic efficiency of the nanocatalyst in two reactions: the synthesis of 3,4‐dihydropyranochromenes from the reaction among aromatic aldehydes, 4‐hydroxycoumarin, and malononitrile, and the synthesis of chromeno[3,4‐b]quinoline‐6‐ones from the reaction among aniline, 4‐hydroxycoumarin, and aromatic aldehydes.

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

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

Magnetic chitosan-functionalized waste carton biochar composites for efficient adsorption of anionic and cationic dyes

In this study, BC-CoFe2O4-CS magnetic composite was successfully prepared from waste cardboard and investigated as an efficient adsorbent for the removal of amaranth and methyl orange in aqueous solution. First, the fibers obtained from the cardboard waste were carbonized by a hydrothermal process to produce biochar. Subsequently, the final magnetic composites were synthesized by in situ growth and Schiff base crosslinking reactions. The composites were characterized by zeta potential, Brunauer–Emmett–Teller measurements, Fourier transform Infrared spectroscopy, Scanning electron microscopy, Energy dispersive spectrometer,X-ray Diffraction, Thermogravimetry analysis and Vibrating sample magnetometer. The effects of adsorbent dosage and initial solution pH on dye removal efficiency were studied. The results showed that the maximum adsorption capacity of amaranth could reach 500.6 mg·g−1 at pH = 2, the adsorbent dosage of 0.5 mg·ml−1, and methyl orange could reach 644.0 mg·g−1 at pH = 4, the adsorbent dosage of 0.5 mg·ml−1. The adsorption process followed the pseudo-second order kinetic models and Langmuir isotherm. BC-CoFe2O4-CS was easily separated from the aqueous solution due to the loading of CoFe2O4 magnetic nanoparticles. Besides, the BC-CoFe2O4-CS could be further used after the adsorption experiments with or without desorption and still showed good adsorption performance in the actual water samples. Therefore, it is expected that the composite material prepared from waste cartons can be used for the treatment of dye-containing wastewater due to its low cost, high efficiency, and simple application.

Exploring the magnetic and supercapacitor characteristics of praseodymium-doped CoFe2O4 magnetic nanoparticles

Exploring the magnetic and supercapacitor characteristics of praseodymium-doped CoFe2O4 magnetic nanoparticles

Overcoming the agglomeration effect of magnetic CoFe2O4 nanoparticles for efficient photocatalysis under collected sunlight

Overcoming the agglomeration effect of magnetic CoFe2O4 nanoparticles for efficient photocatalysis under collected sunlight

Oxovanadium(IV) unsymmetrical salophen complex supported on modified silica-coated CoFe2O4 nanoparticles: A magnetically recoverable nanocatalyst for efficient and selective oxidation of sulfides and thiols

In this study, an oxovanadium(IV) unsymmetrical salophen complex, VO(salophen-OH) where salophen-OH = 4-[(E)-{(2-[(E)-2-hydroxybenzylidene)amino]phenyl}imino)methyl]benzene-1,3-diol, was synthesized and immobilized on the surface of chloro-functionalized silica-coated CoFe2O4 (CoFe2O4@SiO2@CPTMS) magnetic nanoparticles. FT-IR and EDX spectra, TEM and SEM images, XRD pattern, TGA, ICP, and VSM measurements were applied to characterize the resulting CoFe2O4@SiO2@CPTMS@VO(salophen-OH) nanoparticles. The developed CoFe2O4@SiO2@CPTMS@VO(salophen-OH) magnetic nanoparticle was used as a remarkably efficient nanocatalyst, which facilitates the chemo-selective oxidation of sulfides to sulfoxides using 30 % H2O2 and also enables the oxidative coupling of thiols to disulfides using urea/H2O2 (UHP) in ethanol at room temperature. This catalytic system presented disulfides and sulfoxides as optimal products that showed good to excellent yields, and there was no over-oxidation of disulfides and sulfoxides to undesirable by-products. An external magnet can be used to recover this nanocatalyst magnetically, and it can be recycled up to five times in both oxidation reactions without losing its catalytic action. Moreover, the recycled catalyst shows no major differences in its XRD pattern and FT-IR spectrum compared to the fresh catalyst.

Constructing N,S co-doped network biochar confined CoFe2O4 magnetic nanoparticles adsorbent: Insights into the synergistic and competitive adsorption of Pb2+ and ciprofloxacin

To solve the problem of biochar lack of adsorption sites for heavy metal ions and the difficulty of recycling, CoFe2O4 magnetic nanoparticles confined in nitrogen, sulfur co-doped 3D network biochar matrix (C–CoFe2O4/N,S-BC) was designed and fabricated successfully. The obtained C–CoFe2O4/N,S-BC displays remarkable adsorption performance for both Pb2+ and ciprofloxacin (CIP) removal at the single or binary system due to the role of N,S as metal ion anchoring compared to the N,S-free sample (CoFe2O4/BC). N,S co-doped BC not only participates in adsorption reaction but also effectively inhibites the agglomeration of CoFe2O4 nanoparticles and increases the active sites as a carrier at the same time. In the single system, CoFe2O4/N,S-BC demonstrates a fast adsorption rate (equilibrium time: 30 min) and high adsorption capacity (224.77 mg g−1 for Pb2+, 400.11 mg g−1 for CIP) towards Pb2+ and CIP. The adsorption process is befitted pseudo-second-order model, and the equilibrium data are in great pertinence with Langmuir model. In the binary system, the maximum adsorption capacity of CoFe2O4/N,S-BC for Pb2+ and CIP is 244.80 mg g−1 (CIP: 10.00 mg L−1) and 418.42 mg g−1 (Pb2+: 10.00 mg L−1), respectively. The adsorption mechanism is discussed based on the experimental results. Moreover, C–CoFe2O4/N,S-BC shows good practical water treatment capacity, anti-interference ability and stable reusability (the removal efficiency＞80% after eight cycles). The rapid, multifunctional, reusable, and easily separable adsorption properties make C–CoFe2O4/N,S-BC promising for efficient environmental remediation. This study also offers a viable method for the construction of adsorption material for complex wastewater treatment.

Enhancing wettability and adhesive properties of PVDF-based substrates through non-thermal helium plasma surface modification

Polyvinylidene fluoride (PVDF) has gained attention as a promising material for tissue engineering due to its biocompatibility and piezoelectricity. However, achieving proper cell adhesion to PVDF surfaces remains a challenge. This study focuses on the preparation and characterization of PVDF-based substrates, including PVDF thin films and nanocomposites incorporating CoFe2O4 magnetic nanoparticles. Helium plasma treatment is employed to modify the surface properties of these substrates. The plasma treatment induces significant changes in the topography of the PVDF-based nanocomposites. The roughness values of the samples increase from 2–3 nm to 14–17 nm after 90 s of plasma treatment, leading to enhanced hydrophilicity with an average contact angle below 60°. Importantly, the helium plasma treatment preserves the magnetic and structural properties of the substrates, suggesting the retention of their magnetoelectric properties and, thus treated composites hold potential for remote stem cell activation. We provide evidence of cytocompatibility and improved adhesive properties of plasma-treated substrates using human mesenchymal stem cell cultures.

Photocatalytic decomposition of methylene blue and methyl orange dyes using pistachio biochar/CoFe2O4/Mn-Fe-LDH composite as H2O2 activator

Photocatalysis has gained a lot more notice due to its simplicity, cost-effectiveness, and efficiency, especially for dye degradation. In this study, a novel composite (PBC/CoFe2O4/Mn-Fe-LDH) including pistachio biochar (PBC), CoFe2O4 magnetic nanoparticles, and Mn-Fe-layered doubled hydroxide (LDH) was produced using a co-precipitation method. The composite was utilized to remove methylene blue (MB) and methyl orange (MO) dyes from aqueous solutions by the photodegradation method. The Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) analyses were used for characterization of the desired samples. The designed variables were pH (2-10), concentration of dye (10-30 mg.L−1), photocatalyst amount (0.2-1 g.L−1), H2O2 quantity (10-50 µL/100 mL), and time (10-50 min). The maximum degradation of MB and MO at optimal conditions (pH: 2 for MO and 10 for MB, dye concentration: 10 mg.L−1, catalyst mass: 1 g.L−1, time: 50 min, H2O2 value: 30 μL/100 mL) was obtained 99.10% and 99.89%, respectively. The scavenger effect investigation indicated that the species of OH• and O2•−, and h+ have the main function in the MB and MO degradation. The data were well explained by the pseudo-first-order kinetic model, and the constants for MB and MO dye elimination were established as 0.060 min−1 and 0.056 min−1, respectively. The PBC/CoFe2O4/Mn-Fe-LDH as a novel and promising composite could be useful for dye degradation in the photocatalytic reactor.

Magnetic nitrogen-doped carbon nanofibers containing homogeneously dispersed CoFe2O4 nanoparticles with lightweight and efficient microwave absorption performance

Homogeneously dispersed ultrafine CoFe2O4 nanoparticles embedded within N-doped carbon nanofibers (named as CFO@NCNFs) have been fabricated via electrospinning and following heat treatment procedures. The dielectric and magnetic parameters of CFO@NCNFs/paraffin wax composites are regulated through adjusting the concentration of CoFe2O4 to obtain good impedance matching and excellent microwave absorption (MA) properties. Benefiting from the unique structure involving CoFe2O4 @onion-like carbon nanospheres and 3D conductive NCNFs network, as well as the synergistic mechanism between ultrasmall magnetic CoFe2O4 nanoparticles and light mass dielectric NCNFs. The CFO@NCNFs-5 exhibit outstanding MA properties at only 20 wt% filler loading and minimum reflection loss (RL) achieves −47.9 dB (surpass 99.9% MA) at 9.2 GHz with a thin thickness of merely 1.7 mm, and the corresponding effective absorption bandwidth (RL < −10 dB) achieves 5.4 GHz (6.5–11.9 GHz). Moreover, the effective absorption bandwidth (EAB) can be obtained in multiband (3.9–18.0 GHz) by adjusting the thickness of sample layer. Our work indicates that the appropriate incorporation of ultrafine CoFe2O4 nanoparticles encapsulated in NCNFs is a versatile and high-efficiency strategy to integrate lightweight and excellent properties of magnetic carbon-based absorbers.

Design of a ternary magnetic composite based on a covalent organic framework and Ag nanoparticles for simultaneous photodegradation of organic pollutants under LED light irradiation: Application of BBD-RSM modeling and resolution of spectral overlap of analytes

Designing novel photocatalysts is crucial in improving pollutant removal and promoting a cleaner and healthier environment. The main objective of this study was to create a novel magnetic core-shell structure that could be used for photocatalytic applications. To achieve this goal, we used CoFe2O4 magnetic nanoparticles as the core and a covalent organic framework (COF) as the shell, which was designed to have magnetic properties and a suitable surface for further functionalization. To improve its photocatalytic properties, we added silver nanoparticles (Ag NPs) by a facile light-assisted reduction process to create a ternary composite. The presence of Ag NPs is expected to result in a broader absorption range of light and more effective degradation of pollutants through plasmonic sensitization and the transfer of bandgap energy into the visible light spectra. We characterized the prepared composite using various chemical and physical techniques, and then examined its ability to remove two stable organic pollutants, methylene blue (MB) dye and 4-nitrophenol (4-NP), simultaneously. The strong spectral overlap between these pollutants posed a challenge for conventional spectroscopic methods to accurately measure their concentration. To overcome this, a rapid and new method, namely extended ratio subtraction method (EXRSM), was utilized to separate and remove the spectral overlap. We further optimized the reaction conditions using response surface methodology (RSM) modeling techniques. Our findings indicated that the designed composite was capable of degrading organic pollutants under the visible light radiation of an LED lamp.

CoFe2O4 magnetic nanoparticles: Synthesis by thermal decomposition of 8-hydroxyquinolinates, characterization, and application in catalysis

CoFe2O4 magnetic nanoparticles: Synthesis by thermal decomposition of 8-hydroxyquinolinates, characterization, and application in catalysis

Sulfonated Silica Coated CoFe2O4 Magnetic Nanoparticles for the Synthesis of 3,4-Dihydropyrimidin-2(1H)-One and Octahydroquinazoline Derivatives

Sulfonated-silica-coated cobalt ferrite (CoFe2O4) magnetic nanoparticles (MNPs-SiCoFe-SO3H) are efficient heterogeneous catalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazoline derivatives in the absence of solvent. The effects of solvent, temperature, and catalyst amount on the reaction are investigated. The easy separation, reusability of the catalyst, simplicity of the procedure, mild reaction conditions, and good yields (68–95%) within short reaction times (15–70 min) are the advantages of this method. The catalyst can be reused up to eight times with not much loss of activity. Scanning electron microscopy images, X-ray diffraction spectra, and elemental analysis of the recycled catalyst show that the catalyst is stable after the reaction.

Optimization of ultrasound-assisted removal of crystal violet dye, Cu(II), and Cd(II) ions by magnetic CoFe2O4 nanoparticles using central composite design

In this study, magnetic CoFe2O4 nanoparticles (CFO NPs) were fabricated by coprecipitation method for the removal of crystal violet (CV), Cu(II) and Cd(II) from environmental water samples in batch mode. This study investigated the effect of CFO NPs on the removal of CV, Cu(II), and Cd(II) using the response surface methodology (RSM) based on central composite design (CCD). For this purpose, batch experiments were designed and performed to evaluate the effect of variables such as pH, adsorbent amount, sonication time, and concentration of pollutants using RSM. Under optimal conditions (ultrasound time of 17 min, pollutant concentration of 15 mg L−1, CFO NPs amount of 0.24 g, and pH = 6), the removal efficiency was achieved in the range of 95.86–99.82%. Evaluating the reusability of the CFO NPs showed that the CFO NPs adsorbent can be reused for up to 5 cycles while maintaining its high efficiency in removing CV, Cu(II) and Cd(II). The removal efficiency of CV, Cu(II) and Cd(II) was obtained in the range of 91.68–97.59% for real samples. Overall, the results revealed that CFO NPs adsorbent has a high ability to remove CV, Cu(II) and Cd(II) from different water samples.

Determination of hexanal and heptanal in saliva samples by an adapted magnetic headspace adsorptive microextraction for diagnosis of lung cancer

In this work, an analytical method for the determination of two endogenous aldehydes (hexanal and heptanal) as lung cancer biomarkers in saliva samples is presented for the first time. The method is based on a modification of magnetic headspace adsorptive microextraction (M–HS–AME) followed by gas chromatography coupled to mass spectrometry (GC-MS). For this purpose, an external magnetic field generated by a neodymium magnet is used to hold the magnetic sorbent (i.e., CoFe2O4 magnetic nanoparticles embedded into a reversed-phase polymer) in the headspace of a microtube to extract the volatilized aldehydes. Subsequently, the analytes are desorbed in the appropriate solvent and the extract is injected into the GC-MS system for separation and determination. Under the optimized conditions, the method was validated and showed good analytical features in terms of linearity (at least up to 50 ng mL−1), limits of detection (0.22 and 0.26 ng mL−1 for hexanal and heptanal, respectively), and repeatability (RSD ≤12%). This new approach was successfully applied to saliva samples from healthy volunteers and those with lung cancer, obtaining notably differences between both groups. These results reveal the prospect of the method as potential diagnostic tool for lung cancer by saliva analysis. This work contributes to the Analytical Chemistry field presenting a double novelty: on the one hand, the use of M–HS–AME in bioanalysis is unprecedentedly proposed, thus expanding the analytical potential of this technique, and, on the other hand, the determination of hexanal and heptanal is carried out in saliva samples for the first time.