MnFe2O4 Nanoparticles Research Articles

Multi-characteristic optimization and modeling analysis of Cu2+ removal from wastewater using activated coke/MnFe2O4 magnetic composite

This study used pyrolytic coke (PC) as a viable source for producing an adsorbent. The surface magnetization of activated coke (AC) with MnFe2O4 nanoparticles was carried out to remove Cu2+ from aqueous media after PC activation via a chemical activation method. The structural and surface properties of the adsorbents were examined using a variety of analyses, including thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), Burner-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) mapping, Raman, vibrating-sample magnetometry (VSM), atomic force microscopy (AFM), and dynamic light scattering-zeta potential (DLS-ZP). Several parameters were investigated to determine the efficacy of the adsorption process: initial Cu2+ concentration (10–50 mg/L), pH (2−10), adsorbent dosage (0.75–3.75 g/L), temperature (25–65 °C), and contact time (30–150 min). Response surface methodology-central composite design (RSM-CCD) and artificial neural network-genetic algorithm (ANN-GA) methods were used to optimize the process and have correlation coefficients of 0.9890 and 0.9943, respectively. Optimum conditions were determined at an initial Cu2+ concentration of 40 mg/L, a pH of 7.61, an adsorbent dosage of 0.75 g/L, a temperature of 55 °C, and a contact time of 150 min using the RSM-CCD approach. The adsorption process efficiency for AC and AC/MnFe2O4 magnetic composite was determined to be 90.24 and 99.06 %, respectively. According to the results, the adsorption capacity of AC/MnFe2O4 was 72.71 mg/g. The Cu2+ adsorption using magnetic composites followed the Elovich kinetic model. Thermodynamic studies revealed that the process is endothermic and spontaneous. Adsorption efficiency decreased for all adsorbents when Ca2+ and Na+ ion concentrations in aqueous solutions rose. As the number of steps in the adsorption/desorption process increases, the adsorption marginally reduces. Adsorbents' ability to adsorb Cu2+ ions in multi-metallic solutions compared to single-metallic solutions has diminished. The results showed that the AC/MnFe2O4 adsorbent has a high capacity to adsorb-desorb Cu2+ and remove polluted effluent. Additionally, actual wastewater treatment outcomes demonstrated the AC/MnFe2O4 magnetic composite's high efficacy in removing Cu2+ ions.

Determination of Rhodium in Soil by Dispersive Solid-Phase Extraction (DSPE) with Manganese Ferrite Nanoparticles and Flame Atomic Absorption Spectrometry (FAAS)

Manganese ferrite (MnFe2O4) nanoparticles-assisted dispersive solid-phase extraction (MF-DSPE) was developed for the determination of rhodium (Rh) in soil samples at low levels with good accuracy and precision by flame atomic absorption spectrometry (FAAS). The synthesis of MnFe2O4 nanoparticles was carried out in a microwave system by a rapid procedure. The pH, buffer volume, sorbent mass, sample volume, eluent volume/concentration, and mixing time were identified with univariate optimization. Under the optimal conditions, the limits of detection (LOD) and quantitation (LOQ) were 4.4 and 14.7 µg L−1, respectively. The sensitivity was improved by 121.9-fold based upon comparison of the limits of detection with and without preconcentration. The applicability was investigated by spiking rhodium into soil extracts, and good recovery results between 91.2% and 122.2% were achieved using matrix matching calibration. The results showed that MF-DSPE-FAAS determines low levels of rhodium in soil with good accuracy and precision.

MnFe2O4/zeolite composite catalyst for activating peroxymonosulfate to efficiently degrade antibiotic

To design a catalyst with high catalytic activity and reusability for activating peroxymonosulfate (PMS) to degrade antibiotic, magnetic MnFe2O4/zeolite (MFZ) catalyst was prepared by one-pot co-precipitation hydrothermal method. Comprehensive characterizations indicate MnFe2O4 nanoparticles were supported on the surface of Na-A zeolite. The saturation magnetization of MFZ is 12.85 emu/g, which is sufficient for magnetic solid–liquid separation. The removal of tetracycline in MFZ/PMS oxidation system could reach 96.4%, which was more than 2.7 times of that using PMS alone. And after 5 cycles, the degradation could still reach 80.4%. Mechanism analysis suggests that 1O2 and O2•- played predominant roles in the advanced oxidation process.

Spinel manganese nanoferrite for X-ray/gamma radiation shielding, display and antimicrobial applications

MnFe2O4 (MnFO) nanoparticles (NPs) were produced by solution combustion method. To determine phase purity, functional group, surface morphology, structural analysis, and energy band gap, synthesized NPs were evaluated using several methods. The formation of cubic MnFO NPs with the Fd−3m space group and absence of other impurities is confirmed by PXRD Bragg’s reflection. Using Wood and Tauc’s relation, the direct energy band gap is found to be 1.1 eV which was further confirmed with DFT theory. Photoluminescence, CIE and CCT plots shows, MnFO might be a good nanophosphor material for display applications. The X-ray/gamma ray shielding characteristics of MnFO nanoparticles were also evaluated in the energy range 0.081–1.332 MeV. The theoretical and the measured shielding parameters are compared. Furthermore, antimicrobial, antibacterial, antifungal and anticancer activities are discussed in detail. NPs might finds an application in the display technology, shielding of X-ray/gamma ray.

Effect of Cu doping on the structural and magnetic properties of MnFe2O4 nanoparticles

Effect of Cu doping on the structural and magnetic properties of MnFe2O4 nanoparticles

Highly efficient removal of toxic As(V), Cd (II), and Pb(II) ions from water samples using MnFe2O4@SBA-15-(CH2)3-adenine as a recyclable bio-nanoadsorbent

Millions of people nowadays are exposed to highly toxic ions, including arsenic, cadmium, and lead, which all have detrimental effects on human health and cause irreparable damage to the nature and health of living species. It is, therefore, absolutely crucial to remove these toxic ions from ecosystems. Herein, a sponge-like bio-nanocomposite with a core-shell-shell structure consisting of magnetic MnFe2O4 nanoparticles (NPs) as core and mesoporous silica (SBA-15) functionalized with the nucleobase adenine (Ade) as a shell was synthesized to be applied for the adsorptive removal of toxic ions from aqueous media. The prepared material was characterized using various techniques, such as FTIR, XRD, TEM, VSM, and BET. Under optimum conditions, the MnFe2O4@SBA-15@(CH2)3-Ade removed As(V), Cd(II), and Pb(II) ions with greater than 96% efficiency. The kinetic and equilibrium data were satisfactorily described by the pseudo-second-order and the Redlich-Peterson models. The maximum adsorption capacities for As(V), Cd(II), and Pb(II) were calculated to be 21.99 mg g−1, 29.62 mg g−1, and 31.01 mg g−1, respectively. Also, the bio-nanocomposite showed ion removal efficiencies of over 95% during the seventh cycle of adsorption-desorption. Pb (II) ions had a stronger affinity for the active sites of the bio-nanoadsrobent when all of the studied systems (mono-, bi-, and multi-component) were compared. In addition, the practical application of the bio-nanocomposite for ion capture was evaluated in groundwater and industrial wastewater samples. Based on the findings of this study, the MnFe2O4@SBA-15@(CH2)3-Ade can be considered a promising adsorbent for the fast and efficient removal of heavy metals from water matrices.

In-situ fabrication of manganese ferrite grafted polyaniline nanocomposite: A magnetically reusable visible light photocatalyst and a robust electrode material for supercapacitor

Herein, we reported the in-situ preparation of manganese ferrite (MnFe2O4) grafted polyaniline (Pani), a magnetic nanocomposite for the potential visible light photocatalytic material as well as electrode material for supercapacitor. The physical characterization of the prepared nanoparticle and nanocomposite was examined with various spectroscopic and microscopic analyses. The peaks observed in the X-ray diffraction study confirm the face-centered cubic phase of MnFe2O4 nanoparticles with a grain size of ∼17.6 nm. The surface morphology analysis revealed the uniform distribution of spherical-like MnFe2O4 nanoparticles on the surface of Pani. The degradation of malachite green (MG) dye under exposure to visible light was investigated using MnFe2O4/Pani nanocomposite as a photocatalyst. The results exposed the faster degradation of MG dye was accomplished by MnFe2O4/Pani nanocomposite than MnFe2O4 nanoparticles. The energy storage performance of the MnFe2O4/Pani nanocomposite was analyzed through cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy analyses. The results exposed that the MnFe2O4/Pani electrode achieved a capacitance of 287.1 F/g than the MnFe2O4 electrode (94.55 F/g). Further, the respectable capacitance of 96.92% was achieved even after 3000 repetitive cycles stability . Based on the outcomes, the MnFe2O4/Pani nanocomposite can be suggested as a promising material for both photocatalytic and supercapacitor applications.

Self-assembled multilayer Nb2C MXene/MnFe2O4 electrochemical sensor with Schottky junctions for the detection of acetaminophen and dopamine

The electrochemical sensors with the ability of biomolecule detection can be used for human life and health monitoring. In this work, we developed an electrochemical sensor with a Schottky junction by electrostatic interaction, composed of Nb2C MXene and MnFe2O4. Large reactive groups (O, OH, Cl, or F) are observed at the ends of the Nb2C MXene surface. Meanwhile, there are abundant oxygen vacancies and surfaces of MnFe2O4 which bring it favorable heterogeneous catalytic properties. Among them, the chemical self-assembly of MnFe2O4 nanoparticles on Nb2C MXene enhances the binding strength of the material through electrostatic interaction, promotes charge transfer across the interface, and modulates the electronic and nanostructural characteristics of the N-MFO (MnFe2O4/Nb2C MXene). The results demonstrate that the sensing performance of N-MFO4 for Acetaminophen (AP) and Dopamine (DA) is significantly improved compared to Nb2C MXene and MnFe2O4 modified electrodes, respectively. The obtained limits of detection (LOD) of N-MFO4 modified electrode for AP and DA being 0.079 and 0.070 μM, respectively. The combination of electrodes modified with highly active nanomaterials is supposed to build a portable electrochemical analysis system with high sensitivity, good selectivity, favorable stability, simple operation and low cost, and promote the application of electrochemical sensors in related fields.

Experimental Study on the Heat Transfer Performance of Nanofluid MnFe<sub>2</sub>O<sub>4</sub> - Ethylene Glycol/Water on Double-Pipe Heat Exchanger

The heat exchanger is an example of heat transfer applications in industries that commonly found in cooling systems and powerplants. The heat exchangers utilise water, oil, and ethylene glycol (EG) as heat transfer fluids which possess a deficiency in heat transfer characteristics. Nanofluid are expected to improve the heat characteristics of the fluid used in heat exchangers. This research used MnFe2O4 nanoparticles with a volume fraction of 0.05% into the base fluid. The base fluid is a mixture of EG-water with a concentration of 20; 40; 60; and 80%. This study aims to understand the heat transfer characteristics of the MnFe2O4-EG/water nanofluid. The experiments were carried out on a double-pipe heat exchanger with variations flow rate 0.2; 0.4; and 0.6 l/min. This study is expected to show the best performance of MnFe2O4-EG/water nanofluid.

Magnetization, Band Gap and Specific Heat of Pure and Ion Doped MnFe2O4 Nanoparticles

We have studied the magnetic properties of ion doped MnFe2O4 nanoparticles with the help of a modified Heisenberg model and Green’s function theory taking into account all correlation functions. The magnetization Ms and the Curie temperature TC increase with decreasing particle size. This is the opposite behavior than that observed in CoFe2O4 and CoCr2O4 nanoparticles. By Co, Mg or Ni doping, Ms and TC increase with enhancing the dopant concentration, whereas, by La or Gd doping, the opposite effect is obtained due to the different doping and host ionic radii which change the exchange interaction constants. The band gap energy Eg is calculated from the s–d model. It can decrease or increase by different ion doping. The peak observed in the temperature dependence of the specific heat at TC is field dependent.

Assessment of structural, morphological, and optical properties of MnFe2O4 nanoparticles and MnFe2O4-layered 2D structures elaborated by e-beam technique

Assessment of structural, morphological, and optical properties of MnFe2O4 nanoparticles and MnFe2O4-layered 2D structures elaborated by e-beam technique

Genetic algorithm-assisted artificial neural network modelling for remediation and recovery of Pb (II) and Cr(VI) by manganese and cobalt spinel ferrite super nanoadsorbent

MnFe2O4 and CoFe2O4 nanoparticles were hydrothermally synthesized to examine their capability in adsorption of Pb (II) and Cr (VI). The adsorbents exhibited a high rate of adsorption, reaching 90% of their adsorption capacity in less than 30 min. Furthermore, the adsorption capability of the Magnetic Nanoparticles (MNPs) was noticeably greater at initial pollutant concentrations smaller than 40 mg/L. Maximum adsorption capacity on MnFe2O4 and CoFe2O4 nanoparticles were 40 and 25.38 mg/g for Cr (VI) and 523.32 and 476.19 mg/g for Pb (II), respectively. A data-driven model of Artificial Neural Network was used for prediction of adsorption capacity at both equilibrium and non-equilibrium condition. The model parameters including the numbers of neuron (n = 7) and data portioning for training (49.5%), validation (40.5%), and testing (10%) were obtained using Genetic Algorithm. The results indicated that the model could predict the data with high accuracy (R2 = 0.998). The input parameters were initial concentration, time, pH, temperature, adsorbent dosage, and other parameters that is dependent to the physico-chemical properties of ions and adsorbents’ surface (ε, α1, α2). The mechanism involved in Cr(VI) and Pb(II) adsorption are electrostatic physisorption and a combination of ion exchange chemisorption and electrostatic physisorption, respectively. Desorption capability and adsorbent reuse capability were also examined.

Highly Sensitive Magnetoelastic Biosensor for Alpha2-Macroglobulin Detection Based on MnFe2O4@chitosan/MWCNTs/PDMS Composite

The need for Alpha2-Macroglobulin (α2-M) detection has increased because it plays an important role in the diagnosis of diabetic nephropathy (DN). However, few sensors can realize the high-sensitive detection for α2-M with characteristics of being fast, flexible, wearable and portable. Herein, a biosensor based on a MnFe2O4@chitosan/MWCNTs/PDMS composite film was developed for α2-M detection. Due to the excellent magnetoelastic effect of MnFe2O4 nanoparticles, the stress signal of the biosensor surface induced by the specific antibody-antigen binding was transformed into the electrical and magnetic signal. Chitosan-coated MnFe2O4 particles were used to provide biological modification sites for the α2-M antibody, which simplified the conventional biological functionalization modification process. The MnFe2O4@chitosan particles were successfully prepared by a chemical coprecipitation method and the property was studied by TEM, FT-IR and XRD. MWCNTs were employed to enhance electrical conductivity and the sensitivity of the biosensor. The detection limit (LOD) was reduced to 0.1299 ng·mL-1 in the linear range from 10 ng∙mL-1 to 100 µg·mL-1, which was significantly lower than the limit of health diagnostics. The biosensor is fabricated by a simple method, with advantages of being rapid and highly-sensitive, and having selective detection of α2-M, which provides a novel method for the early diagnosis of DN, and it has potential in the point of care (PoC) field.

Mechanical performance and thermal stability of hardened Portland cement-recycled sludge pastes containing MnFe2O4 nanoparticles

This study focused on investigating the possibility of using different ratios (5, 10, 15 mass%) of recycled alum sludge (RAS) as partial replacement of ordinary Portland cement (OPC), to contribute to solving the problems encountered by cement production as well as stockpiling of large quantities of water-treated sludge waste. MnFe2O4 spinel nanoparticles (NMFs) were used to elaborate the mechanical characteristics and durability of different OPC-RAS blends. The outcomes of compressive strength, bulk density, water absorption, and stability against firing tests fastened the suitability of utilization of RAS waste for replacing OPC (maximum limit 10%). The inclusion of different doses of NMFs nanoparticles (0.5, 1 and 2 mass %) within OPC–RAS pastes, motivates the configuration of hardened nanocomposites with improved physico-mechanical characteristics and stability against firing. Composite made from 90% OPC–10% RAS–0.5% NMFs presented the best characteristics and consider the optimal choice for general construction applications. Thermogravimetric analysis (TGA/DTG), X-ray diffraction analysis (XRD), and scanning electron microscope (SEM) techniques. affirmed the positive impact of NMFs particles, as they demonstrated the formation of enormous phases as ilvaite (CFSH), calcium silicate hydrates (CSHs), MnCSH, Nchwaningite [Mn2 SiO3(OH)2 H2O], [(Mn, Ca) Mn4O9⋅3H2O], calcium aluminosilicate hydrates (CASH), Glaucochroite [(Ca, Mn)2SiO4, and calcium ferrite hydrate (CFH). These hydrates boosted the robustness and degradation resistance of the hardened nanocomposites upon firing.

Efficient removal of Cr(VI) by the modified biochar with chitosan schiff base and MnFe2O4 nanoparticles: Adsorption and mechanism analysis

Cr(VI) contained the characteristic of water solubility, mobility and cell permeability in aqueous solution. As a result, the treatment of Cr(VI) in aqueous solution was very necessary before it was discharged into water body. A novel adsorbent of the modified biochar with chitosan schiff base and MnFe2O4 nanoparticles (CsSB/MnFe2O4@BC) was prepared, characterized and applied into the elimination of Cr(VI) by batch adsorption process. CsSB/MnFe2O4@BC composites were characterized by some technologies (Such as SEM, TEM, XRD and FT-IR). The results showed that it was an irregular, wavy and heterogeneous surface, and it contained MnFe2O4 nanoparticles and functional groups of C−H, O−H and C−O−C stretching vibrations. The operational parameters (For example, pH, concentration of Cr(VI), contact time and temperature) had an important influence on the adsorption capacity of Cr(VI) removal. The adsorption processes were best fitted to Pseudo-second order model and Freundlich model. Additionally, the maximum uptake capacity of Cr(VI) ions reached 125.34 mg/g. The possible mechanisms were ion exchange, surface complexation, electrostatic attraction, and pore adsorption. After five cycles, adsorption capacity of Cr(VI) by CsSB/MnFe2O4@BC still remained high, and reached 102.45 mg/g. Therefore, it was a simple, economical, efficiency and reuse adsorbent and could be used as an high efficient adsorbent in the treatment of Cr(VI) in aqueous solution.

Synthesis and Gas Sensing Properties of Manganese Ferrite Nanoparticles by Sol - Gel Method

The purpose of this study is to determine the effect of temperature on the microstructure of Manganese Ferrite (MnFe2O4) nanoparticles. The synthesis of MnFe2O4 (MFO) nanoparticles carried out by using sol - gel citrate method followed by calcinations. The nanocomposite was characterized by means of x-ray powder diffraction. Obtained XRD measurement data was crystalline in phase with a spinel structure. Additionally, sensor performance of undoped and surface modified by 1.5 wt % Pd over MFO were studied under different operating temperature and different reducing gases such as NH3, H2S, CO and ethanol. The result reveals that material exhibit excellent sensitivity and selectivity toward ammonia gas at 1800C proving their applicability in gas sensors.

Synthesis and photothermal applications of MnFe2O4 nanoparticles

Synthesis and photothermal applications of MnFe2O4 nanoparticles

A Simplified and Efficient Method for Production of Manganese Ferrite Magnetic Nanoparticles and Their Application in DNA Isolation.

A simplified, fast, and effective production method has been developed for the synthesis of manganese ferrite (MnFe2O4) magnetic nanoparticles (MNPs). In addition to the wide applicability of MnFe2O4 MNPs, this work also reports their application in DNA isolation for the first time. An ultrasonic-cavitation-assisted combustion method was applied in the synthesis of MnFe2O4 MNPs at different furnace temperatures (573 K, 623 K, 673 K, and 773 K) to optimize the particles' properties. It was shown that MnFe2O4 nanoparticles synthesized at 573 K consist of a spinel phase only with adequate size and zeta potential distributions and superparamagnetic properties. It was also demonstrated that superparamagnetic manganese ferrite nanoparticles bind DNA in buffer with a high NaCl concentration (2.5 M), and the DNA desorbs from the MNPs by decreasing the NaCl concentration of the elution buffer. This resulted in a DNA yield comparable to that of commercial DNA extraction products. Both the DNA concentration measurements and electrophoresis confirmed that a high amount of isolated bacterial plasmid DNA (pDNA) with adequate purity can be extracted with MnFe2O4 (573 K) nanoparticles by applying the DNA extraction method proposed in this article.

Ultrasonic irradiation-assisted MnFe2O4 nanoparticles catalyzed solvent-free selective oxidation of benzyl alcohol to benzaldehyde at room temperature.

Magnetic nanoparticles (NPs) play a vital role in heterogeneous catalysis because of their easy separation, and effective recyclability. Herein, we report the synthesis of MnFe2O4 NPs for use as catalysts in the selective oxidation of benzyl alcohol to benzaldehyde under mild conditions. The MnFe2O4 NPs have been synthesized by precipitation method followed by hydrothermal ageing at 180 °C for 4.0 h. We have investigated the effect of chitosan and carboxymethyl cellulose on the size or morphology of the formed MnFe2O4 NPs. The X-ray diffraction study confirms the formation of pure and crystalline MnFe2O4 with varying average crystallite sizes ranging from 18 to 28 nm based on the type of additive used. The electron microscopy study reveals that the additive plays a significant role in controlling the morphology of the formed MnFe2O4 NPs. These MnFe2O4 NPs exhibit superparamagnetic behaviour at room temperature and can effectively catalyze the solvent-free selective oxidation of benzyl alcohol to benzaldehyde in the presence of tert-butyl hydroperoxide at room temperature under ultrasonic irradiation. The developed protocol can be extended to various substituted benzyl alcohols having both the electron withdrawing and electron donating groups to afford moderate to excellent yield of the products. The catalyst is magnetically retrievable, highly stable, and can be reused up to the sixth run without significant loss of catalytic activity.

Heterogeneous photo-Fenton process over magnetically recoverable MnFe2O4/MXene hierarchical heterostructure for boosted degradation of tetracycline

Heterogeneous photo-Fenton technology is a kind of technology based on the in-situ generation of highly active and oxidized free radicals that can degrade most of the organic pollutants. As for the study, MnFe2O4/MXene (Ti3C2Tx) composites were obtained from a simple calcination strategy for photo-Fenton degradation of tetracycline (TC). The results of the characterization exhibit that MXene nanosheets could uniformly dispersed MnFe2O4 nanoparticles, which both improved the utilization rate of visible light over MnFe2O4 and effectively alleviate the agglomeration of MnFe2O4 nanoparticles as a support. The optimal sample (MT-10) displays the outstanding degradation efficiency (93.8%) of TC under the conditions of TC concentration (10 mg/L), catalyst dosage (100 mg/L), H2O2 dose (0.4 mL) and pH value (pH = 3). In addition, the as-prepared MnFe2O4/MXene composite also shows good cycle stability, magnetic recovery, and low biotoxicity. These findings expand the scope of MXene in synthesizing and designing efficient and stable composite material in environmental remediation field.