Search

MoS2@Fe3O4 composite was fabricated via two-step hydrothermal method, utilizing cetyltrimethyl ammonium bromide(CTAB) as a soft template, thioacetamide as a sulfur source, and sodium molybdate as a molybdenum source. The morphology and structure of MoS2@Fe3O4 were analyzed by SEM and XRD. The efficiency and mechanism of catalytic degradation of iodoprolol(IPM) by MoS2@Fe3O4/H2O2 system was evaluated. The results showed that Fe3O4 was deposited on the surface of MoS2, and MoS2@Fe3O4 had a uniformly dispersed flower ball structure, which provided more catalytic active sites. Under the conditions of initial pH of 4, MoS2@Fe3O4 dosage of 0.15 g/L, H2O2 concentration of 0.5 mmol/L, and IPM concentration of 5 μmol/L, the degradation rate of IPM by MoS2@Fe3O4/H2O2 system reached 89.85% after 30 minutes of reaction. Compared with Fe3O4/H2O2 system, the degradation rate of IPM increased by about 12%. The applied magnetic field facilitated the reusability of MoS2@Fe3O4. The main active species for IPM degradation by the MoS2@Fe3O4/H2O2 system were ·OH and 1O2. The degradation rate of the MoS2@Fe3O4/H2O2 system on IPM remained stable over 80% after 6 cycles, suggesting that MoS2@Fe3O4 had good stability.

Abstract A microbial fuel cell (MFC) is a modern, environmentally friendly, and cost-effective energy conversion technology that utilizes renewable organic waste as fuel, converting stored chemical energy into usable bioelectricity in the presence of a biocatalyst. Despite advancements in MFC technology, several challenges remain in optimizing power production efficiency, particularly regarding anode materials and modifications. In this study, low-cost biosynthesized iron oxide nanoparticles (Fe3O4 NPs) were coated with a polyaniline (PANI) conducting matrix to synthesize hybrid Fe3O4/PANI binary nanocomposites (NCs) as modified MFC anodes via an in-situ polymerization process. Characterization techniques, including UV–Vis, XRD, SEM, and FT-IR, revealed the successful synthesis of green-routed nano-scaled materials with altered optical properties after matrix coating, high crystallinity in the iron oxide phase, rougher surface morphology, and characteristic Fe–O peaks at 594 cm⁻1. Additionally, the electrochemical behavior of the prepared nano-materials was characterized by cyclic voltammetry (CV), where low ΔEp values (0.473 V) for Fe3O4/PANI NCs indicated the presence of reversible charge transfer mechanisms at the electrode surface, reflecting a high rate of electron transfer. The synthesized nanocomposite was used to modify pencil graphite anodes to construct four single-chamber MFCs: bare pencil graphite anodes, pencil graphite anodes modified with Fe3O4, PANI, and Fe3O4/PANI nanocomposites. The maximum open circuit voltage (OCV) value was 645 ± 24.50 mV, with a high power output of 424.51 ± 6.86 mW/m2 and current density of 2475.01 ± 1.23 mA m−2 produced by the Fe3O4/PANI NCs modified pencil graphite electrode, which is more than six times the efficiency in terms of power density compared to the unmodified pencil graphite electrode (PGE). These results demonstrate that the synthesized nanocomposite plays an effective and value-added role in modifying traditional carbon anode electrodes within an MFC energy conversion device system.

Fe3O4 nanoparticles (NPs) with a continuous and mesoporous silica (m-SiO2) shell were synthesized using a one-step method, sourcing silica from rice husk ash (RHA). The rice husk was thermally treated to obtain ash, from which silica was extracted as sodium silicate and precipitated by pH reduction. This silica powder, combined with iron chloride salts, facilitated the synthesis of the core-shell NPs. Mint extract acted as a capping agent to prevent agglomeration, and CTAB (cetyltrimethylammonium bromide) was used to create the porous SiO2 shell. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) characterization investigated the structure, size, and shell formation. Coating integrity and suspension stability were assessed through Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS). DLS analysis showed a relatively narrow particle size distribution with an average hydrodynamic size of 72.6 nm. Small-angle X-ray scattering (SAXS) provided insights into the meso- and nanoscale structure, while BET and nitrogen adsorption-desorption isotherms confirmed the mesoporous nature of the silica shell. Magnetization measurements showed superparamagnetic behavior, with specific magnetization values of 57.9 emu/g for Fe3O4 and 27.5 emu/g for Fe3O4@m-SiO2. These results confirm the successful synthesis of superparamagnetic magnetite NPs with a mesoporous silica coating from RHA.

Abstract Background The progression of triple-negative breast cancer is shaped by both tumor cells and the surrounding tumor microenvironment (TME). Within the TME, tumor-associated macrophages (TAMs) represent a significant cell population and have emerged as a primary target for cancer therapy. As antigen-presenting cells within the innate immune system, macrophages are pivotal in tumor immunotherapy through their phagocytic functions. Due to the highly dynamic and heterogeneous nature of TAMs, re-polarizing them to the anti-tumor M1 phenotype can amplify anti-tumor effects and help mitigate the immunosuppressive TME. Results In this study, we designed and constructed an ultrasound-responsive targeted nanodrug delivery system to deliver Siglec-G siRNA and Fe3O4, with perfluorohexane (PFH) at the core and mannose modified on the surface (referred to as MPFS@NDs). Siglec-G siRNA blocks the CD24/Siglec-G mediated “don’t eat me” phagocytosis inhibition pathway, activating macrophages, enhancing their phagocytic function, and improving antigen presentation, subsequently triggering anti-tumor immune responses. Fe3O4 repolarizes M2-TAMs to the anti-tumor M1 phenotype. Together, these components synergistically alleviate the immunosuppressive TME, and promote T cell activation, proliferation, and recruitment to tumor tissues, effectively inhibiting the growth of primary tumors and lung metastasis. Conclusion This work suggests that activating macrophages and enhancing phagocytosis to remodel the TME could be an effective strategy for macrophage-based triple-negative breast cancer immunotherapy.

This study investigates the production of TiO2/Fe3O4/C hydrophilic magnetic nanocomposites produced via a one-step novel method using the submerged arc discharge method applied in liquid media of ethanol and ethanol–ammonia under the influence of external magnetic field. The magnetized submerged arc discharge forms a longer-lasting plasma arc, thereby affecting the growth of spherical and tubular carbon nanocomposites. More reactive species enrolled in the carbon growth in the magnetized submerged arc discharge, resulting in the ordered crystalline structure. The nanocomposites synthesized in ethanol–ammonia show hydrophilic characteristics, indicated by their dispersion improvement in the water and the presence of the vibrations of hydroxyl, amine, and –CN functional groups in Fourier transfer infrared (FTIR) spectra. The preparation technique described in this study using magnetized submerged arc discharge is supposed to be a simple and less costly preparation method that can potentially be further applied to produce numerous other nanocomposites.

Effects of Fe-based nanoparticles (Fe2O3 and Fe3O4) on germination parameters were studied for some seedling characteristics of Oriental beech (Fagus orientalis) seeds. Fe2O3 and Fe3O4 nanoparticle applications were made at concentrations of 400, 800, 1200, 1600, and 2000 mg/L on Fagus orientalis seeds collected from 10 different populations, and some germination and seedling characteristics were evaluated. Preliminary results generally indicated that low-dose nanoparticle applications positively affected germination and seedling characteristics, while increases in doses led to decreases in these parameters. Values obtained from high-dose nanoparticle applications were generally lower than those from the control group. The iron nanoparticles affected the parameters to different extents, Fe2O3 nanoparticles showed a significant positive effect on germination rate and radicle length, while exhibiting a significant negative effect on germination percentage and plumule length. The populations least affected by high-dose iron nanoparticle applications were Bursa Inegol, Karabuk-Yenice, and Ordu Akkus, while the most affected were the Bartin-Kumluca and Kahramanmaras-Andirin populations.

Abstract A novel composite material, magnetic chitosan-clay/benzoin/Fe3O4 (CS-CY/Benz/Fe3O4), was synthesized for effectively removing thionine dye (TH) from water solutions. The structural integrity and suitability of CS- CY/Benz/Fe3O4 composite for adsorption purposes were validated through extensive characterization techniques including BET, XRD, FTIR, and SEM. The adsorption efficiency was optimized through a Box–Behnken design (BBD) employing response surface methodology (RSM), focusing on variables such as adsorbent dose (A: 0.02–0.08 g), solution pH (B: 4–10), temperature (C: 30–60 °C), and time (D: 5–30 min). Experimental results revealed a maximum TH removal of 99% with significant interactions between temperature (C) and time (D) (p-value = 0.0001). The optimal conditions for TH removal were determined as pH ~ 5.91, adsorbent dosage of 0.08 g, temperature of 54.34 °C, and time of 29.7 min. The investigation of kinetics revealed that the adsorption process conformed to a pseudo-second-order (PSO) model, while the equilibrium data were effectively described by the Freundlich isotherm model. At a temperature of 333.15 K and a TH concentration of 350 mg/L, the adsorption capacity was determined to be 660.86 mg/g. The mechanism of adsorption encompassed various interactions such as electrostatic attractions, n–π interactions, hydrogen bonding, and Yoshida H-bonding. Particularly, the CS-CY/Benz/Fe3O4 composite demonstrated strong magnetic responsiveness, enabling straightforward separation from water using an external magnetic field after adsorption. Particularly, the CS-CY/Benz/Fe3O4 composite demonstrated strong magnetic responsiveness, enabling straightforward separation from water using an external magnetic field after adsorption. This research contributes important findings to the advancement of magnetic chitosan-based composites for efficient removal of TH dye pollutants from water environments.

Abstract This article is devoted to the synthesis of a new magnetic palladium catalyst that has been immobilized on A-TT-Pd coated-magnetic Fe3O4 nanoparticles. Such surface functionalization of magnetic particles is a promising method to bridge the gap between heterogeneous and homogeneous catalysis approaches. The structure, morphology, and physicochemical properties of the particles were characterized through different analytical techniques, including TEM, FT-IR, XRD, SEM, EDS, TGA-DTG, ICP, and VSM techniques. The obtained Fe3O4@SiO2@A-TT-Pd performance can show excellent catalytic activity for the synthesis of diaryl ethers and oxidation of sulfides, and the corresponding products were obtained with high yields. The advantages of this catalyst include a simple test method, green reaction conditions, no use of dangerous solvents, short reaction time, low catalyst loading, and reusability. Also, the nanocatalyst was easily separated from the reaction mixture with the help of a bar magnet and recovered and reused several times without loss of stability and activity.

High spin polarization and low resistivity of Fe3O4 at room temperature have been an appealing topic in spintronics with various promising applications. High-quality Fe3O4 thin films are a must to achieve the goals. In this report, Fe3O4 films on different substrates (SiO2/Si(100), MgO(100), and MgO/Ta/SiO2/Si(100)) were fabricated at room temperature with radio-frequency (RF) sputtering and annealed at 450 °C for 2 h. The morphological, structural, and magnetic properties of the deposited samples were characterized with atomic force microscopy, X-ray diffractometry, and vibrating sample magnetometry. The polycrystalline Fe3O4 film grown on MgO/Ta/SiO2/Si(100) presented very interesting morphology and structure characteristics. More importantly, changes in grain size and structure due to the effect of the MgO/Ta buffering layers have a strong impact on saturation magnetization and coercivity of Fe3O4 thin films compared to cases of no or just a single buffering layer.

Autoclave corrosion testing has been used for many years; however, few have studied the effect of its shortcomings on the formation of corrosion products and corrosion behaviour. In particular, understanding of these effects under high temperature and high pressure (HTHP) is rare. In this study, we highlighted the important parameters such as heating periods, flow rates and volume-to-surface ratios influencing carbon steel corrosion in the early stages. Especially, characterisation and protection behaviour of corrosion products associated with corrosion behaviour in the heating stage under the geothermal CO2-containing environment were systematically studied via mass loss, in-situ electrochemistry and surface analysis techniques. The roles of pCO2, volume-to-surface ratio and flow rate influence the formation of the corrosion products in the early stage are also evaluated.

Abstract Delivering anticancer drugs to the appropriate site within the body poses a critical challenge in cancer treatment with chemotherapeutic agents like doxorubicin (DOX). Magnetic graphene oxide (GO) nanosheets with generation 1 (G1) amidoamine-dendronized crosslinks were developed by coupling cystamine-functionalized GO nanosheets with Fe3O4 nanoparticles modified with primary amine and methyl acrylate. These magnetic GO nanosheets were loaded with DOX to create a dual pH- and redox-responsive delivery system for cancer chemotherapy. The prepared magnetic nanosheets underwent characterization using FTIR, XRD, DLS, VSM, FE-SEM, and TEM. Physical DOX adsorption was evaluated using various isotherms, including Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich. The in-vitro release profiles of DOX from the magnetic nanosheets were studied under different pH conditions, with and without glutathione (GSH), and the drug release data were fitted with various kinetic models. Additionally, an MTT assay was employed to assess the compatibility and antitumor activity of DOX-loaded magnetic nanosheets in the HepG2 cell line. The results showed that the maximum drug loading was 13.1% (w/w) at a drug/carrier ratio of 1. Without GSH addition, the maximum drug release after 10 days was only 17.9% and 24.1% at pH 7.4 and 5.3, respectively. However, in the presence of GSH, the maximum drug release reached 51.7% and 64.8% at pH 7.4 and 5.3, respectively. Finally, the research findings suggest that the magnetic nanosheets exhibited pH- and redox-stimuli drug release, high biocompatibility, and superior antitumor activity compared to free DOX.

Metal-organic framework (MOF) derived porous Fe3O4/C powders were applied for absorption of microwaves in the frequency range of 1–18 GHz. The effects of the polyvinylpyrrolidone (PVP) additive on the synthesis of MIL101-(Fe) precursor were studied by various characterization methods. By adding PVP, the impure hematite phase (α-Fe2O3) with magnetite phase (Fe3O4) was disappeared and the particular morphology was transformed to the porous rod-like, leading to the increase of specific surface area from 150 to 282 m2/g. Furthermore, the saturation magnetization (Ms) of Fe3O4/C powders reached a maximum value of 47 emu/g at a proper amount of PVP. A thin absorber (2.6 mm) made of 50 wt% Fe3O4/C powders and 50 wt % paraffine absorbed the whole of X frequency band (8–12 GHz) with a minimum reflection loss of −20 dB at a matching frequency of 10 GHz. Adjusting the permittivity and permeability parameters of the Fe3O4/C powders via adding PVP was responsible for their better microwave absorption performance.

The Ag nanoparticles demonstrate potent bacteria eradication capabilities; however, their tendency to aggregate in aqueous solutions compromises the antibacterial efficacy. Furthermore, the Ag nanoparticles employed in sewage treatment are challenging to recycle, resulting in environmental pollution and resource wastage. Herein, the Ag-core Fe3O4-shell structured particles (Ag@Fe3O4) are synthesized by leveraging the reduction potential difference between Ag+/Ag0 and Fe3+/Fe2+ through a one-step polyol reduction process. The Fe3O4 shell in the Ag@Fe3O4 composite not only effectively inhibits the agglomeration of Ag, but also enhances the penetration capability of the composite into biofilms, thereby enabling Ag@Fe3O4 to possess remarkable antibacterial efficacy against Escherichia coli (E. coli). The Ag@Fe3O4 demonstrates nearly 100 % inhibition of E. coli at a concentration of 0.24 mg mL−1 (with an Ag content of 0.042 mg mL−1) while still maintaining antibacterial effectiveness of 74.6 % even after undergoing reutilization for 10 cycles. Meanwhile, due to the excellent electron conductivity of Ag and the effective adsorption capability of Fe3O4 shell towards organic dyes, Ag@Fe3O4 facilitates rapid electron transfer to organic dyes and further lead to their reduction and degradation in the presence of NaBH4. The Ag@Fe3O4 can catalytically degrade various organic dyes (including Rhodamine B, Rhodamine 6G, and Methylene blue) within only 15 min, while achieving an impressive degradation efficiency exceeding 90.9 % after 6 cycles of reutilization. The cost-effectiveness (approximately $0.17 per gram), facile magnetic recovery, along with the superior antibacterial and dye-degradation performance showcase the significant potential of Ag@Fe3O4 for medical applications and sewage treatment.

The Ciujung River, one of the main rivers in Banten province, Indonesia, plays an important role in agriculture and sanitation. However, the increasing use of heavy metals, especially mercury, by industries along the Ciujung River has caused significant environmental pollution. This issue requires considerable attention to ensure that environmental problems can be resolved immediately. This study evaluated the feasibility of Fe3O4 as a potential material to adsorb mercury in Ciujung River water originating from industrial waste. The adsorption efficiency was assessed by examining the effects of pH, adsorbent weight, and contact time. In addition, the adsorption capacity of Fe3O4 was analyzed using adsorption kinetics and isothermal models. The findings of the study showed that the adsorption process of Hg(II) using Fe3O4 followed pseudo-first-order kinetics with an R2 value of 0.998. Furthermore, the research data correlated well with the Freundlich isotherm. After Hg(II) was treated with Fe3O4 for a contact time of 90 min, its concentration in pure water samples was reduced, with an adsorption capacity of 263.04 mg/g. The study also evaluated the reusability and stability of Fe3O4 to reduce Hg(II) in Ciujung River water samples. Fe3O4 achieved a maximum adsorption capacity of 218.17 mg/g and was able to selectively absorb Hg(II) even in the presence of other heavy metals, with a desorption rate of 99.39 %. The desorption rate remained high after the fifth cycle, with a value of 87.65 %. These results indicate that Fe3O4 has strong potential as an adsorbent for treating industrial wastewater from the Ciujung River.

The Fe3O4 magnetite–poly-1H pyrrole dendritic nanocomposite seeded on additional poly-1H pyrrole film, denoted as Fe3O4-P1HP/P1HP, is synthesized by oxidative polymerization utilizing (Fe(NO3)3·5H2O for the pyrrole monomer. The resulting nanocomposite exhibits a notable bandgap of 1.97 eV and demonstrates broad optical absorption up to 625 nm. The structure of each particle consists of numerous smaller internal particles, which are composed of nanofibers of approximately 2.0 nm in length and porous structures of around 5.0 nm. These porous structures cluster together to form a larger configuration, with an overall diameter of ∼230 nm and a length of approximately 300 nm, giving the composite a nano-cactus-like appearance. The fabricated Fe3O4–P1HP/P1HP photocathode is inserted into a three-electrode cell to facilitate green hydrogen production from sanitation water without the need for any external sacrificial agent. The performance of H2 gas generation is assessed by measuring the photocurrent density (J ph) under light, which serves as an indicator of the efficiency of hydrogen production. The J ph value reaches −0.23 mA/cm² under light conditions. The highest J ph values of −0.164 and −0.158 mA/cm² are observed at wavelengths of 340 and 440 nm, respectively. However, as the wavelength reaches 540 nm, the J ph value decreases to −0.134 mA/cm² and drops to its lowest point of −0.128 mA/cm² at 730 nm, which is comparable to the dark current (J o). The fabricated photocathode demonstrates a promising hydrogen generation rate of 90 µmol/h cm², reflecting its potential for commercial applications. The combination of this impressive hydrogen production rate, along with the photocathode’s cost-effectiveness and straightforward fabrication process, suggests that this technology could be commercially viable for converting sanitation water into hydrogen gas.

This study aims to investigate the facile fabrication of Fe3O4/rGO nanocomposites based on the green synthesis method, utilizing Moringa oleifera and Amaranthus viridis extracts for photocatalytic degradation application. The coprecipitation and modified Hummer methods were used to synthesize Fe3O4 and rGO, respectively. Both materials were stirred to connect Fe3O4 on the surface of the rGO sheet to produce a nanocomposite. The nanocomposites as a photocatalyst were characterized to investigate the structural, bonding, optical, and magnetic properties. The X-ray diffraction spectrum of Fe3O4/rGO nanocomposites is cubic inverse spinel with a crystalline size around 10 nm. The transmission electron microscope results show a decrease in particle size of Fe3O4/rGO with the addition of rGO. Fe–O functional groups in the nanocomposite show the presence of Fe3O4 on the rGO surface. The addition of rGO concentration affects the saturation magnetization and coercivity values of the nanocomposites. Meanwhile, the methylene blue degradation efficiency is optimal for Fe3O4/rGO nanocomposites at a concentration of 5:5, reaching 99.3 % degradation during a 3-h photocatalytic process. The magnetic potential of Fe3O4/rGO nanocomposites means that the photocatalyst can be recycled up to three times with a high degradation rate. Therefore, the Fe3O4/rGO nanocomposite has the potential as a reusable, environmentally friendly, and cost-effective photocatalyst for the removal of organic pollutants from wastewater.

Hydroxyapatite (HAp) derived from bioresources has garnered attention due to its advantageous catalytic capabilities. In this study, HAp was synthesized from green mussel shell waste and subsequently composited with Fe3O4 for utilization as a catalyst in the synthesis of spirooxindole-chromene compound. The synthesis and characterization of pristine HAp, Fe3O4, and HAp/PCL/Fe3O4 samples were thoroughly investigated. XRD analysis, coupled with refinement techniques, revealed that pristine HAp crystallized in the P63/m hexagonal structure, while Fe3O4 crystallized in the Fd-3m cubic structure. Additionally, the HAp/PCL/Fe3O4 composite exhibited a combination of both materials properties. SEM-EDX micrographs depicted an irregular morphology for HAp/PCL/Fe3O4 with an average particle size of approximately 156 nm. The catalytic performance of HAp/PCL/Fe3O4 in the synthesis of spirooxindole was evaluated using a one-pot three-component method assisted by ultrasonic irradiation, resulting in the highest yield of 78.54 % within a relatively short time frame. Moreover, the repeated use of HAp/PCL/Fe3O4 as a catalyst led to a negligible decrease in product yield, making it an environmentally friendly catalyst option.

This study explores the use of waste coal fly ash supported with magnetite (FA/Fe3O4) as an environmentally friendly adsorbent for removing Pb metal from aqueous solutions. FA/Fe3O4 composites were synthesized using the ball mill method with varying ratios (9:1, 9:3, and 9:5). The FA/Fe3O4 sample with a 9:3 ratio exhibited the most promising characteristics, including a high surface area (4.878 m2/g), substantial pore volume (2.508 cc/g), large average pore diameter (3.060 nm), low crystallinity (12.98 %), small crystal size (28.41 nm), and non-uniform particle morphology (average size of 2.6 μm). Optimal conditions for Pb removal were achieved with the 9:3 adsorbent, showing 95.50 % adsorption efficiency at 30 mg adsorbent mass, 98.83 % efficiency at pH 4, and 99.45 % efficiency at a concentration of 25 ppm. These findings indicate that FA/Fe3O4 composites provide a highly efficient and straightforward method for Pb removal, offering significant practical value in environmental applications.

A composite catalyst was developed to degrade methylene blue (MB) via the Fenton reaction from Fe3O4 and H2O2 with zeolite-NaY as magnetite support to reduce agglomeration. Hydrothermal and co-precipitation approaches were used to synthesize the composite. The co-precipitation method here was proven to be more suitable to produce the composite. Under optimal conditions, all composite catalysts achieved a remarkable MB reduction (more than 90 %) as confirmed through TLC analysis and UV–Vis spectra. Notably, based on linear regression, FeZ-A maintained over 60 % activity after 15 uses, while FeZ-2 showed the least Fe ion leaching. This demonstrated the effectiveness and stability of the developed catalysts.

Methylene blue pollutants can be treated by photocatalytic methods using metal oxide-based semiconductor materials and metal organic framework (MOF). These two materials are often coupled into a composite to improve their physicochemical properties and catalytic activity. This research focuses on the synthesis of composites based on Cr-PTC MOF, ZnO, and Fe3O4 by the sonochemical method. The obtained composites were characterized and tested for catalytic activity in methylene blue pollutant degradation in an aqueous system under acidic conditions (pH = 5). Our investigation shows that the Cr-PTC@Fe3O4 composite possesses the lowest band gap energy of 1.86 eV and achieves the highest photocatalytic activity in methylene blue degradation at solution pH = 5, with a percent degradation of 84.36%. The sonochemical incorporation of Fe3O4 and Cr-PTC MOF is able to fabricate materials in a short time with better photocatalytic activity in degrading methylene blue than the single materials. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Abstract Today, high-energy applications are devoted to boosting the storage performance of asymmetric supercapacitors. Importantly, boosting the storage performance of the negative electrodes is a crucial topic. Fe3O4-based active materials display a promising theoretical storage performance as a negative electrode. Thus, to get a high storage performance of Fe3O4, it must be tailored to have a higher ionic and electronic conductivity and outstanding stability. Functionalized graphite felt (GF) is an excellent candidate for tailoring Fe3O4 with a facile ionic and electronic pathway. However, the steps of the functionalization of GF are complex and time-consuming as well as the energy loss during this step. Thus, the in-situ functionalization of the GF surface throughout the synthesis of Fe3O4 active materials is proposed herein. Fe3O4 is electrodeposited at the in-situ functionalized GF surface with the crystalline nanowires-like structure as revealed from the various analyses; SEM, TEM, Mapping EDX, XPS, XRD, wettability test, and Raman analysis. Advantageously, the synthetic approach introduces full homogeneous and uniform coverage of the large surface area of the GF. Thus, Fe3O4 nanowires with high ionic and electronic conductivity are characterized by a higher storage performance. Interestingly, Fe3O4/GF possesses a high specific capacity of 1418 mC cm−2 at a potential scan rate of 10 mV s−1 and this value retained to 54% at a potential scan rate of 50 mV s−1 at an extended potential window of 1.45 V. Remarkably, the diffusion-controlled reaction is the main contributor of the storage of Fe3O4/GF electrode as revealed by the mechanistic studies.

Fe3O4 is an internal magnet that can work as a medium for the electrolyte solution in electrochemical hydrogen production to facilitate electron movement. When Fe3O4 is combined with activated carbon made from banana leaves (ACBL), electron transfer occurs between the ACBL aromatic ring and Fe3+ ions from solved Fe3O4, which increases the solution’s conductivity and finally produces more hydrogen. ACBL is a biomass catalyst used as a free parameter to increase the Fe3O4 magnetic field in the solution. The Fe3O4 was synthesized using the coprecipitation method, while ACBL was obtained through an activation process to produce graphene oxide. Graphene oxide in ACBL was characterized using Scanning Electron Microscopy (SEM) EDX, Fourier Transform Infra-Red (FTIR), Brunauer, Emmett, and Teller (BET), and TEM (Transmission Electron Microscopy). BET was used to determine the surface area of ACBL. Hydrogen was produced using the electrolysis method. The SEM results showed that the elemental content of graphene oxide in ACBL was 72.47 %. The graphene oxide in ACBL had a positive charge represented by a bright color on the sample surface. The positive charge was due to the FTIR O-H and C-O groups working with Fe3O4. BET analysis showed that the average pore diameter of ACBL was 1.68 nm. The largest hydrogen production results were obtained at ACBL 200 mesh, which was 15.5 ml. ACBL from abundant biomass has magnetic and electrical potential within its aromatic ring. As the aromatic ring interacts with the magnetic field of Fe3O4, the electromagnetic field of the solution is strengthened. As a result, hydrogen production increases.

Abstract Realizing spin transport between heavy metal and two‐dimensional (2D) magnetic materials at high Curie temperature (TC) is crucial to advanced spintronic information storage technology. Here, environmentally stable 2D nonlayered Fe3O4 nanosheets are successfully synthesized using a reproducible process and found that they exhibit vortex magnetic domains at room temperature. A Verwey phase transition temperature (TV) of ≈110 K is identified for ≈3 nm thick nanosheet through Raman characterization and spin Hall device measurement of the Pt/Fe3O4 bilayer. The anisotropic magnetoresistance ratio decreases near TV, while both the spin Hall magnetoresistance ratio and spin mixing conductance (Gr) increase at TV. As the temperature approaches 112 K, the anomalous Hall effect ratio tends to become zero. The maximum Gr reaches ≈5 × 1015 Ω−1m−2 due to the clean and flat interface between Pt and 2D nanosheet. The observed spin transport behavior in Pt/Fe3O4 spin Hall devices indicates that 2D Fe3O4 nanosheets possess potential for high‐power micro spintronic storage devices applications.

The study investigated the performance of a novel magnetic hybrid MIL-53(Fe)/Fe3O4@TiO2 composite for removing reactive red 195 (RR195) dye from water using UVc light. Various analytical techniques were used to characterize the nanocomposite materials. X-ray diffraction analysis confirmed the presence of MIL-53(Fe) and TiO2 in the composite. FT-IR analysis identified carboxyl and Ti-O-Ti groups in the photocatalyst structure. The study evaluated the effects of pH, dye concentration, photocatalyst dosage, and temperature on RR195 photodegradation. The Langmuir-Hinshelwood kinetic model provided the best fit for the reaction rate. Optimal conditions for an 84 % dye degradation were found at a photocatalyst dose of 15 mg/100 mL, pH 3, dye concentration of 100 mg/L, and 35 °C after 120 minutes of UVc light exposure. Thermodynamic analysis indicated an endothermic reaction with positive values for Δ#H and negative values for Δ#S. The MIL-53(Fe)/Fe3O4@TiO2 composite demonstrated excellent stability and achieved over 90 % dye degradation after five cycles. Overall, the composite shows promise for treating wastewater with dyes.

Because of the conventional bioimaging methods, including ultrasound and X-ray examinations often lack accuracy and sensitivity in the early diagnosis, as a heterogeneous subtype of breast cancer, it remains an urgent need to develop efficaciously and sensitively diagnostic drivers of triple negative breast cancer (TNBC). The overexpression of c-mesenchymal epithelial transition-factor (c-Met) is associated with the basal subtype of breast carcinoma and linked with decreased survival rate of TNBC patients. Here, we have synthesized a dual-modal nanoprobe with luminescence imaging in the bio-window of near infrared II region (NIR II, 1000–1700) and magnetic resonance imaging (MRI) performances. After c-Met targeting binding protein decoration, this Fe3O4@mSiO2-ICG/cMBP had outstanding size stability and preeminent biocompatibility. Meaningfully, it presented effective TNBC cells recognition in vitro. Besides, after caudal-vein injection of this nanoprobe, both NIR II luminescence imaging and MRI demonstrated that it can more efficiently concentrated in metastatic TNBC tumors in comparison with Fe3O4@mSiO2-ICG and clinical used Gd-DTPA. Meanwhile, the core–shell nanoprobes also showed negligible toxicity in vivo. All results suggested that our cMBP modified nanocomposite could provide a fascinating and efficient non-invasive diagnostic tool for TNBC detection in clinic.

The core-shell structure Fe3O4@C magnetic nanoparticles were synthesized with superparamagnetic Fe3O4 nanosphere as a magnetic core, and soluble starch resin as a carbon source via a solvothermal method. Silica-iron oxide and Fe3O4@C carriers with a core-shell structure were prepared by carbonization of organic material on the surface of Fe3O4 nanoparticles, Fe3O4@C supported Pd were processed into magnetic nano-catalysts with core-shell structure, and their catalytic properties were investigated. The resulting environmentally friendly magnetic material can be used to degrade dye wastewater. The structure of magnetic nanoparticles was characterized using TEM, XRD and VSM. The effects of preparation conditions in the structure of the Fe3O4@C magnetic nanoparticles were taken out. The results indicate that from XRD, the magnetic nano particles Fe3O4@C synthesized of carbon sources have amorphous carbon diffraction peak except for all the characteristic peaks of Fe3O4. The saturation magnetization Fe3O4, Fe3O4@SiO2 and Fe3O4@C – 59.14 emu/g, 49.12 emu/g and 27.95 emu/g, respectively.

Abstract Cancer stands as one of the most impactful illnesses in the modern world, primarily owing to its lethal consequences. The fundamental concern in this context likely stems from delayed diagnoses in patients. Hence, detecting various forms of cancer is imperative. A formidable challenge in cancer research has been the diagnosis and treatment of this disease. Early cancer diagnosis is crucial, as it significantly influences subsequent therapeutic steps. Despite substantial scientific efforts, accurately and swiftly diagnosing cancer remains a formidable challenge. It is well known that the field of cancer diagnosis has effectively included electrochemical approaches. Combining the remarkable selectivity of biosensing components—such as aptamers, antibodies, or nucleic acids—with electrochemical sensor systems has shown positive outcomes. In this study, we adapt a novel electrochemical biosensor for cancer detection. This biosensor, based on a glassy carbon electrode, incorporates a nanocomposite of reduced graphene oxide/Fe3O4/Nafion/polyaniline. We elucidated the modification process using SEM, TEM, FTIR, RAMAN, VSM, and electrochemical methods. To optimize the experimental conditions and monitor the immobilization processes, electrochemical techniques such as CV, EIS, and SWV were employed. The calibration graph has a linear range of 102–106 cells mL−1, with a detection limit of 5 cells mL−1.

Abstract The challenges in water treatment include the need for efficient removal of pollutants like nitrate, which poses significant environmental and health risks. Alumina's significance lies in its proven effectiveness as an adsorbent for nitrate removal due to its high surface area and affinity for nitrate ions. This study delves into the synthesis of differen nano-sized γ-alumina (γA1-5) employing diverse precursors and methods, including nepheline syenite, lime, aluminum hydroxide, precipitation, and hydrothermal processes at varying reaction times. Simultaneously, magnetite (Fe3O4) nanoparticles and magnetite/γ-alumina nanocomposites (Fn/γA5) were synthesized using the co-precipitation method with varying weight ratios (n). Our primary objective was to optimize γ-alumina synthesis by comparing multiple methods, shedding light on the influence of different precursors and sources. Hence, a comprehensive adsorption study was conducted to assess the materials’ efficacy in nitrate removal. This study fills gaps in the literature, providing a novel perspective through the simultaneous assessment of magnetite/alumina nanocomposites and pure alumina performance. Structural and morphological properties were studied employing XRD, FT-IR, FESEM, EDX, XRD, and VSM techniques. The conducted experiments for γA5, F5/γA5, and F10/γA5 nanocomposites showcased the optimum pH of 5 and contact time of 45 min for all samples. The influence of nitrate’s initial concentration on the removal percentage was investigated with initial concentrations of 10 ppm, 50 ppm, and 100 ppm. γA5, F5/γA5 and F10/γA5 nanocomposites had 17.3%, 55%, and 70% at 10 ppm, 18%, 55.16%, and 74% at 50 ppm, and 8.6%, 53.1%, and 63%, respectively. The results highlighted that F10/γA5 can be used as a remarkable adsorbent for wastewater treatment purposes.

The activated persulfate (PS) process could produce sulfate radical (SO4·-) and rapidly degrade organic pollutants. The application of Fe3O4 as a promising PS activator was limited due to the rapid conversion of Fe2+ to Fe3+ on its surface. Mo4+ on MoS2 surface could be used as a reducing site to convert Fe3+ to Fe2+, but the separation and recovery of MoS2 was complex. In this study, MoS2/Fe3O4 was prepared to accelerate the Fe3+/Fe2+ cycle on Fe3O4 surface and achieved efficient separation of MoS2. The results showed that MoS2/Fe3O4 was more effective for PS activation compared to Fe3O4 or MoS2, with a removal efficiency of 91.8% for 20 mg·L−1 tetracycline (TC) solution under the optimal conditions. Fe2+ and Mo4+ on MoS2/Fe3O4 surface acted as active sites for PS activation with the generation of SO4•−, •OH, •O2−, and 1O2. Mo4+ acted as an electron donor to promote the Fe3+/Fe2+ cycling and thus improved the PS activation capability of MoS2/Fe3O4. The degradation pathways of TC were inferred as hydroxylation, ketylation of dimethylamino group and C-N bond breaking. This study provided a promising activated persulfate-based advanced oxidation process for the efficient degradation of TC by employing MoS2/Fe3O4 as an effective activator. HIGHLIGHTS MoS2/Fe3O4 was an effective, recoverable PS activator for tetracycline degradation.; TC was removed by free radical and non-free radical degradation pathways.; Mo4+ promoted the regeneration of Fe2+ on the Fe3O4 surface.;

The iron (III) Schiff base complex was immobilized on magnetic silica as well as mesoporous silica substrates and characterized by XRD, TEM, FT-IR, AAS, VSM techniques, and in the case of mesoporous silica, it was also identified with N2 adsorption/desorption and TGA methods. These materials were applied for oxidation of benzyl alcohols and sulfides with hydrogen peroxide as a green oxidant. The effect of catalyst structures was studied in the mentioned reactions. The results showed that using of mesoporous silica in the oxidation of sulfides and benzyl alcohols with hydrogen peroxide in the optimal reaction conditions provided a higher catalytic yield in the same or even less reaction time, The higher catalytic performance of the mesoporous substrate based on the identifications (carried out by N2 adsorption/desorption technique) can be attributed to the higher surface area of this substrate and the stronger connection of the Schiff base complex of iron (III) to the mesoporous silica (according to leaching test).

A new and efficient Cu(II)-containing mesoporous nanocatalytic system was synthesized by direct immobilization of copper metal powder on the Fe3O4@EDTA nanocomposite. The as-prepared Fe3O4@EDTA@Cu(II) nanocomposite was then characterized by FT-IR, XRD, SEM, TEM, SEM-based EDX and elemental mapping, XPS, TGA, VSM, and also BET and BJH analyses. The resulting Fe3O4@EDTA@Cu(II) mesoporous nanocomposite exhibited satisfactory catalytic activity towards the reduction and one-pot reductive acetylation of nitroarenes and also N-acetylation of arylamines in water at 60 °C. Notably, the applied Cu(II)-containing nanocatalyst was efficiently recovered from the reaction mixture using an external magnetic field and could be reused successfully for five cycles. The protocol developed in this study offers several advantages in terms of mild reaction conditions, simple workflows, using water as a green solvent, and easy recovery and catalyst reuse, making it more ecologically and economically attractive.

The presence of chromium [Cr(VI)] and lead [Pb(II)] ions in the water bodies have adverse effects on humans and aquatic life. Graphene oxide-based magnetic nanocomposites synthesized in the presence of chitosan (mGO/CS) or polyaniline (mGO/PA) as potential adsorbents for the removal of Cr(VI) and Pb(II) ions. The FTIR (Fourier transform infrared spectroscopy), EDX (Energy dispersive X-ray), XRD (X-ray diffraction) and SEM (Scanning electron microscopy) were employed to investigate the chemical composition, structural, elemental analysis, crystalline size and morphology of the nanocomposites. The FTIR results confirmed the synthesis of the nanocomposites by detecting peaks of specific functional groups. The average crystallite sizes of the mGO, mGO/CS, and mGO/PA nanocomposites were 17, 25, and 23 (nm), respectively, as determined by the Debye-Scherrer equation from the XRD data. Batch adsorption experiments were conducted for Pb(II) and Cr(VI) removal by varying the variables like pH, concentration of metal ions and contact time. The Box Behnken design (BBD) was used to optimize the adsorption parameters. Under the optimum conditions, mGO/CS and mGO/PA showed maximum removal percentages (%R) of 92.36 and 98.7 for Pb(II), and 85.25 and 93.08 for Cr(VI), respectively. The adsorption capacities were 110.84 and 118.44 mg/g for Pb(II), and 87.74 and 111.7 mg/g for Cr(VI) were obtained for mGO/CS and mGO/PA, respectively. The pseudo-second-order kinetic model and Langmuir isotherm fitted well to the experimental data and explain the adsorption mechanism of the nanocomposite materials for both metal ions.

The rapid industrial growth has led to increased production of wastewater containing pollutants like heavy metals and organic compounds. These pollutants pose risks to human health and the environment if not properly treated. Engineered nanocatalyst materials (ENMs) are a burgeoning technology that show promise for treating industrial wastewater. Metal oxide ENMs, such as Fe3O4@β-cyclodextrin and Fe3O4@TiO2, have demonstrated efficient removal of heavy metals and methylene blue from wastewater. Fe3O4@TiO2 was found to be more effective than Fe3O4@β-cyclodextrin in removing these pollutants. The highest removal efficiencies were observed at a concentration of 40 mg/g and pH 8. Copper showed the highest removal efficiency (160.5 mg/g), followed by nickel (77.09 mg/g), lead (56.0 mg/g), and cadmium (46.05 mg/g). For methylene blue, the highest removal efficiency was also observed at a concentration of 40 mg/g and pH 8 (91.16 %). Lead (90.5 %), copper (90.48 %), nickel (83.34 %), and cadmium (77.58 %) were also efficiently removed. These findings highlight the potential of Fe3O4@TiO2 as a promising material for industrial wastewater treatment, offering cleaner and safer water for human health and the environment. ENMs have the potential to revolutionize wastewater treatment processes.

This study investigates the sorption of 2-methyl orange dye onto octadecylamine-modified iron oxide magnetic nanoparticles (ODA-IONPs). The synthesized ODA-IONPs exhibit remarkable sorption capacity, reaching 800 mg/g at the nanoparticle concentrations ranging from 5 to 10 mg/g and pH of 2–8. The sorption process demonstrates rapid kinetics, achieving 90% of maximum sorption within 0.5 min. Thermodynamic analysis showed that sorption process is spontaneous and endothermic, as indicated by negative ΔG and positive ΔH values. The pseudo-second-order and Langmuir models best describe the sorption kinetics at 293 K (R² 0.99). Compared to other adsorbents, ODA-IONPs show superior MO removal capacity under a wider pH range. The influence of nanoparticle concentration, pH, and temperature on sorption efficiency is systematically explored, with optimal conditions identified at 10 mg/L ODA-IONPs and pH 6. Furthermore, the feasibility of nanoparticle reusability for sorption purposes is assessed. These findings underscore the potential of ODA-IONPs as efficient sorbents for wastewater treatment and environmental remediation applications.

This study aims to synthesize Fe3O4 nanoparticles using iron rust and evaluate the catalyst's ability in spiropiperidine synthesis. Fe3O4 was synthesized using the thermal decomposition method with palmitic acid as a capping agent. Characterization techniques, including XRD, IR, SEM-EDX, TEM, and PSA confirmed the formation of magnetic Fe3O4 with a well-defined cubic crystal structure, displaying a size of approximately 8.5 nm. Under optimal conditions, spiropiperidine synthesis using the Fe3O4 catalyst achieved an 84.2 % yield and could be reused for up to five runs. These findings highlight the potential of Fe3O4 as an efficient and reusable catalyst for green synthesis applications.

This study addresses the challenging issue of water pollution caused by the non-biodegradable organic compound methylene blue (MB) by synthesizing Fe3O4/SiO2 composite using SiO2 derived from rice husk ash (RHA) for MB photodegradation. The SiO2 was prepared from RHA at various heat treatment temperatures of 750, 800, 850, 900, and 950 °C that resulted in samples A, B, C, D, and E, respectively. The Fe3O4/SiO2 composites were then synthesized using the RHA-derived SiO2 as a precursor, resulting in samples 1 to 5. Various characterizations were conducted, including X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Vibrating Sample Magnetometer (VSM), and Fourier Transform Infrared (FTIR). The photodegradation activity of Fe3O4/SiO2 was tested with UV–Visible spectroscopy. XRD pattern of SiO2 derived from RHA revealed a broad diffraction peak at 2θ of 21.52°, confirming the presence of amorphous SiO2. Meanwhile, all of the composite samples showed peaks corresponding to Fe3O4 and SiO2. FTIR analysis of the composite also verified the existence of SiO2 and Fe3O4. SEM images of RHA-derived SiO2 (samples A-E) showed an ununiform shape, while the composite samples showcased a homogeneous morphology. The EDS results showed the RHA-derived SiO2 (samples A-E) consisted of C, O, Si, Zn, and Cl, while Fe3O4/SiO2 composite samples (samples 1–5) comprised elements Fe, O, C, Si, Zn, and Cl. Superparamagnetic properties also showed in Fe3O4/SiO2 samples 1, 3, and 5, according to the VSM analysis with sample 5 exhibiting the highest saturation magnetization. Among the Fe3O4/SiO2 composites, sample 4 exhibited the highest performance as a photocatalyst for degrading MB.

To enhance the degradation rate of methylene blue (MB) in water, ultrasonication and solvothermal methods were used to prepare Fe3O4/ZIF-9 composite catalysts. The morphology of the catalyst revealed the attachment of cubic ZIF-9 particles to spherical-like Fe3O4 particles. The particle sizes of these ZIF-9s slightly varied, which might be due to the influence of the increased number of nucleation sites originating from the addition of Fe3O4 on the nucleation and growth of ZIF-9s as well as the effects of the variation in Fe3O4/Co salt ratio on the nucleation quantity and growth rate of ZIF-9s. Using this catalyst at a Fe3O4/Co salt molar ratio of 1∶1, 95.1% of the MB was degraded within 30 min. Its pseudo-first-order kinetic constant for a 10-min catalytic reaction reached 0.101 min−1, and it remained stable and had high catalytic performance within the pH range from 5 to 9. X-ray photoelectron spectroscopy results showed that the valence state changes of Fe and Co in Fe3O4/ZIF-9 after MB degradation, verifying the electron transfer between the Fe and Co sites. Meanwhile, the divalent unsaturated Fe and Co sites in the Fe3O4/ZIF-9 structure were likely to synergistically transfer electrons based on the fast degradation kinetics mentioned above. Consequently, compared with the pure ZIF-9, the addition of Fe ions can effectively reduce the reduction potential of Co ions and accelerate the valence state changes of Co ions and the corresponding redox cycle. Furthermore, electron paramagnetic resonance results demonstrated that Fe3O4/ZIF-9 can activate peroxymonosulfate to generate singlet oxygen (1O2), sulfate radicals(SO\begin{document}${}_4^- $\end{document}·), and hydroxyl radicals (·OH), with 1O2 being the primary active species, as further confirmed by the free radical quenching test. Hence, such a redox cycle of Fe and Co sites continuously generated 1O2, SO\begin{document}${}_4^- $\end{document}·, and ·OH, which degraded the MB molecules into carbon dioxide and water. Moreover, a saturation magnetization value of 7.6 A·m2·kg−1 was measured using the vibrating sample magnetometer method, indicating that the Fe3O4 imparts good ferromagnetic properties to the composite catalyst, facilitating its collection and recovery after the catalytic reaction. In addition, after four cycles of use, the catalyst maintained its structure and high degradation rate without significant changes, thereby demonstrating excellent reusability. In conclusion, this study systematically explored the influence of the Fe3O4/Co salt molar ratio on the structure and catalytic performance of the catalyst, qualitatively analyzed the active species during catalysis, and further elucidated the mechanism by which Fe3O4/ZIF-9 improves the catalytic efficiency. This study offers insight into techniques for the organic dye remediation.

In this study, the flat sheet membranes including the neat polyethersulfone (PES) and the mixed matrix membranes (MMMs) containing 20 wt. % polyethersulfone (PES) and various amounts of Fe3O4 nanoparticles were prepared using wet phase inversion and conventional casting methods. Manganese ion rejection and permeate flux as a performance evaluation of the prepared membranes was studied and compared. The characteristics of the fabricated membranes and the synthesized nanoparticles were fulfilled by transmission electron microscopy, field emission scanning electron microscopy and contact angle measurement. The operational parameters such as polymer concentration, pressure, pH, manganese ion concentration and time for manganese ion rejection and permeability were firstly optimized on the neat PES membrane. In the next steps, the performance of the fabricated MMMs containing various amount of Fe3O4 nanoparticles and PES (20%wt.) was evaluated and compared under these optimized conditions. Under the optimal conditions obtained for the rejection of manganese ions by neat PES, the fabricated MMMs had better performance than the neat PES membrane. Also, the results showed that the best performance of the prepared MMMs with the manganese rejection percentage of 89.3% and permeate flux of 28.7 L.m-2.h was found to belong to the PES membranes containing 0.1 wt.% of Fe3O4.

Biomass waste candlenut shells, such as adsorbent carbon, can be utilized. Fe3O4 has great electrical conductivity, and ZIF-67 has diverse pores. Activated carbon, Fe3O4, and ZIF-67 were prepared to obtain a combination of these materials using the co-precipitation method. FTIR spectra show a peak at 1341 cm−1, which depicts the Fe-O bending vibration. At peak 1558 cm−1 shows C = N streching. The top of 1412 cm−1 and 991 cm−1 extend the full ring. The sp2 aromatic peak may be seen at 1150 cm-1C-H bond. The surface area is 17.76 m2/g, and the pore size is 14.99 nm. Coercivity is 119.63 Oe, which shows a strong magnet. The highlight of the study was activated carbon from biomass waste candlenut shells (Aleurites moluccana) doped ZIF-67 supported Fe3O4 with specific capacitance shows high. The diffusion percentage shows fewer electrolyte ions entering the active material, and resistance also showed low results. It can increase the percentage of capacitive ions, thus improving the electrode. Electrochemical results show 1335F/g of high specific capacity at 1 A/g current density. It indicates a suitable candidate material for supercapacitor electrodes.

Abstract Dyes pollution is a serious environmental problem and heterogeneous catalysis has been proposed as a remediation method. In this study, a set of catalysts of synthetic mordenite with iron oxides was synthesized by a simple chemical co-precipitation method assisted by subsequent thermal treatment with an oxidation process. Physicochemical characterization of prepared materials was performed by a variety of techniques, including XRD, SEM, EDS, S BET , UV–Vis DR, and XPS. Photocatalytic methylene blue (MB) degradation by the synthesized catalyst was evaluated with visible light excitation. From the studied set of catalysts, the sample prepared with a thermal treatment at 100 °C in air atmosphere for 3 h was capable of degrading ~ 90% of MB after 120 min with visible light of λ = 420 nm exposition and a small portion of H2O2 added. The catalyst used three processes to degrade MB: (1) adsorption of organic residues in the mordenite matrix support for electrostatic interactions, (2) photocatalysis heterogeneous reaction with visible light and (3) Fenton reaction catalyst with a small portion to H2O2 by Fe3O4–Fe2O3 presence. The catalytic efficiency to dye degradation was improved by a simple and economical thermal treatment without changing reaction conditions like pH, temperature, dose, or other. Studied mordenite iron oxide catalysts can be retrieved and reused at least five times without noticeable degradation, taking advantage of their magnetic properties. These catalysts could be proposed an economical, simple, and non-toxic alternative for eliminating organic dye pollution using visible light or solar irradiation in wastewater remediation related to textile, food, and pharmaceutical industries.

Free-living N2-fixing bacteria are essential in the soil because they provide a source of nitrogen in the form of ammonium needed by plants to be used in building protein blocks. The fixation of free N2 needs to be increased by adding nanomaterials such as magnetite (Fe3O4), which has an active group and can be a source of nitrogenase enzyme cofactor. In this study, increased N2 fixation used N2-fixing bacteria in Burks medium. This increase was determined by measuring NH3 levels using the Phenate method formed after Burks medium was treated with Fe3O4 and chitosan-magnetite (CS-Fe3O4). The study found that the number of bacteria can be well decreased. This research showed that using Fe3O4 and CS-Fe3O4 increased NH3-N levels in cultures of free-living nitrogen-fixing bacteria by 15.40% and 75.54%. For future development, it can be in the form of optimization, the effect of adding the same material to plant secondary metabolites, and the mechanism of bacteria in using the material.

AbstractMagnetic Fe3O4 nanoparticles were prepared via a simple hydrothermal method and utilized to load paclitaxel. The average particle size of Fe3O4 nanoparticles was found to be 20.2 ± 3.0 nm, and the calculated saturation magnetization reached 129.38 emu/g, verifying superparamagnetism of nanomaterials. The specific surface area and pore volume were 84.756 m2/g and 0.265 cm3/g, respectively. Subsequently, Fe3O4@mSiO2 nanoparticles were successfully fabricated using the Fe3O4 nanoparticles as precursors with an average size of 27.81 nm. The relevant saturation magnetization, zeta potential, and specific surface area of Fe3O4@mSiO2-NH2-FA were respectively 76.3 emu/g, −14.1 mV, and 324.410 m2/g. The pore volume and average adsorption pore size were 0.369 cm3/g and 4.548 nm, respectively. Compared to free paclitaxel, the solubility and stability of nanoparticles loaded with paclitaxel were improved. The drug loading efficiency and drug load of the nanoformulation were 44.26 and 11.38%, respectively. The Fe3O4@mSiO2-NH2-FA nanocomposites were easy to construct with excellent active targeting performance, pH sensitivity, and sustained-release effect. The nanoformulation also showed good biocompatibility, where the cell viability remained at 73.8% when the concentration reached 1200 μg/mL. The nanoformulation induced cell death through apoptosis, as confirmed by AO/EB staining and flow cytometry. Western blotting results suggested that the nanoformulation could induce iron death by inhibiting Glutathione Peroxidase 4 (GPX4) activity or decreasing Ferritin Heavy Chain 1 (FTH1) expression. Subsequently, the expression of HIF-1α was upregulated owing to the accumulation of reactive oxygen species (ROS), thus affecting the expression of apoptosis-related proteins regulated by p53, inducing cell apoptosis.

Graphene oxide (GO) and Fe3O4 super paramagnetic material are good candidate for some applications such as drug delivery. It has been shown that combining Fe3O4 with graphene oxide increases the biological efficiency of GO. The use of novel assisted reproductive technologies such as gonadotropins injection has been able to help the fertility of infertile people, but the side effects of these methods and high costs are still problems. The aim of the present study was to investigate the effect of magnetic graphene oxide (MGO) on the in vivo maturation of mouse oocytes. Thirty 6–8-week old female Naval Medical Research Institute (NMRI) mice were treated with intra peritoneal (I.P) injection of MGO mixed with hormones. 12 h after I.P. injection of MGO mixed with PMSG and HCG, the number of metaphase II (MII) oocytes obtained from the left fallopian tubes was counted in each group. Also, immuno-cytochemical staining of glutathione and morphometric analysis of ovaries were studied. The results of this study showed that the simultaneous use of MGO, pregnant mare serum gonadotropin (PMSG), and human chorionic gonadotrophin (HCG) increases the number of MII oocytes and helps to increase maturation of oocytes. It could be concluded that MGO can increase the efficiency of super ovulating hormones due to increase in adsorption of serum hormones and growth factors.

The present work proposes a method for the synthesis of a nanoparticle with a superparamagnetic Fe3O4 core coated with SiO2-NH2 by ultrasound-assisted coprecipitation. Additionally, the nanoparticle is functionalized with a microinflammation biomarker peptide, and its effects on the viability of monkey kidney endothelial cells and the Vero cell line were evaluated. The main physicochemical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), a vibrating sample magnetometer (VSM), a field emission scanning electron, Scanning Electron Microscopy (SEM), and High-Resolution Transmission Electron Microscopy (HR-TEM). The results showed that the nanoparticles are spherical, with sizes smaller than 10 nm, with high thermal stability and superparamagnetic properties. They also demonstrated cell viability rates exceeding 85% through Magnetic Resonance Imaging (MRI). The results indicate the potential of these nanoparticles to be used as a contrast agent in magnetic resonance to detect mild brain lesions.

Contaminated water has remained an unsolved problem for decades, particularly when the contamination derived from heavy metals. A possible solution is to mix the contaminated water with magnetic nanoparticles so that an adsorption process can take place. In that frame, Tesla valve micromixer and Fe3O4 magnetic nanoparticles were selected to perform simulations for encounter maximum mixing efficiency. These simulations focus on inlet velocities ratios between contaminated water and nanoparticles and inlet rates of nanoparticles. The maximum mixing efficiency was 44% for the inverse double Tesla micromixer found for the combination of Fe3O4 nanoparticles as the inlet rate and with inlet velocity ratios of VpVc=10.

In this work, we theoretically and experimentally study the induction of electromagnetic forces in an opal-based magnetic photonic glass, where light normally impinges onto a disordered arrangement of SiO2 spheres by the aggregation of Fe3O4 nanoparticles. The working wavelength is 633 nm. Experimental evidence is presented for the force that results from forced oscillations of the photonic structure. Finite-element method simulations and a theoretical model estimate the magnetic force volumetric density value, peak displacement, and velocity of oscillations. The magnetic force is of the order of 56 microN, which is approximately 500-times higher than forces induced in dielectric optomechanical photonic crystal cavities.

Background: Magnetic nanoparticles attract increasing interest due to their use in cancer therapy and as drug carriers for several other diseases. The present study investigates the physiochemical properties of quercetin-conjugated superparamagnetic Fe3O4 nanoparticles and their effects on breast cancer cell line MCF-7. Methods: A simple precipitation method was used to prepare the Poly Ethylene Imine (PEI)-coated Fe3O4 nanoparticles; they were then conjugated with flavonoid-compound quercetin on the surface via carboxylic/amine group using nanoprecipitation method. Then, the physical and chemical parameters were calculated using Zeta-sizer, scanning electron microscopy (SEM), and extract release patterns at 37 and 42 0C. Finally, the toxicity level of this quercetin- conjugated nanosystem on the MCF-7 cells was investigated by MTT assay. Results: The results showed that the prepared nanosystem attained about 74% of quercetin inclusion, 91.2 nm size, 65.1 mV zeta potential, spherical morphology and a controlled release. Compared to Fe3O4 nanoparticles and pure quercetin, MTT and microscopy analysis revealed that quercetin-conjugated Fe3O4 nanoparticles induced considerable cytotoxicity, and morphology changes against MCF7 cells. Conclusion: Quercetin-conjugated Fe3O4 nanoparticles have appropriate physiochemical properties; they can be a suitable carrier for drug delivery and a promising therapy for candidates. Corresponding Author:Bibi Fatemeh Haghiralsadat View Orcid in Profile You can search for this author in PubMed Google Scholar Profile

Nano-sized Fe3O4 particles were continuously synthesized in the rotating packed bed with blade packings where the rotational speed was set at 1800 rpm, the liquid flow rate of aqueous FeCl2/FeCl3 was kept at 0.5 L/min, and the liquid flow rate of aqueous NaOH was maintained at 0.5 L/min with the chemical co-precipitation route that the synthesis temperature was fixed at 25 °C, the FeCl2 concentration was fixed at 0.15 mol/L, the FeCl3 concentration was fixed at 0.3 mol/L, and the NaOH concentration was fixed at 1.2 mol/L. The average crystallite size and mean particle size of the as-synthesized nano-sized Fe3O4 particles were 12.7 nm and 10.9 nm, respectively. The rate of continuous synthesis of nano-sized Fe3O4 particles was 23.6 kg/day. The as-synthesized nano-sized Fe3O4 particles exhibited a superparamagnetic characteristic at 25 °C. Furthermore, the saturation magnetization of the as-synthesized nano-sized Fe3O4 particles was 66.4 emu/g. The as-synthesized nano-sized Fe3O4 particles had the Type-IV isotherm for N2 adsorption-desorption with a BET specific surface area of 109.4 m2/g. The maximum Orange G adsorption capacity of the as-synthesized nano-sized Fe3O4 particles at 25 °C and pH 3 was 55.0 mg/g. This maximum Orange G adsorption capacity was much higher than that (5.7 mg/g) of the commercial nano-sized Fe3O4 particles that were purchased from Sigma-Aldrich (SA-Fe3O4) because the as-synthesized nano-sized Fe3O4 particles had a smaller mean particle size than SA-Fe3O4. Accordingly, the as-synthesized nano-sized Fe3O4 particles are a promising magnetic adsorbent in the removal of Orange G from water.

The synthesis of oxides using plant extracts as precursors has attracted attention as it is an economical, efficient, and ecological route. Euterpe oleracea Mart, available in the Legal Amazon, has great potential due to its composition, rich secondary metabolites. Therefore, this work aimed to investigate the potential of aqueous açaí leaf extract as precursors in synthesizing FexOy-type oxides. The synthesis was developed in two stages to obtain the hematite phases (step 1) and the magnetite phase (step 2). The effect of pH on phase formation and structure was evaluated in step 1. Then, the material was obtained in step 2 by precipitation with pH adjustment. The powders were characterized by thermal analysis, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The results showed that pH played a significant role in the thermal behavior, crystallite sizes, and structural parameters of hematite, with neutral or acidic pH being more attractive for obtaining crystallites between 21 and 24 nm. Magnetite with 21.51 nm crystallites was precipitated, indicating possible capping of the Fe3O4 particles and preserving their magnetic characteristics.

In this study, a new type of highly efficient and recyclable magnetic-fluorine-containing polyether composite demulsifier (Fe3O4@G-F) was synthesized by the solvothermal method to solve the demulsification problem of oil–water emulsion. Fe3O4@G-F was successfully prepared by grafting fluorinated polyether onto Fe3O4 and graphene-oxide composites. Fe3O4@G-F was characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Taking the self-made crude-oil emulsion as the experimental object, the demulsification mechanism of the demulsifier and the influence of external factors, such as the temperature and pH value, on the demulsification performance of the demulsifier are discussed. The results show that the demulsification efficiency of the Fe3O4@G-F emulsion can reach 91.38% within 30 min at a demulsifier dosage of 750 mg/L, pH of 6, and a demulsification temperature of 60 °C. In neutral and acidic environments, the demulsification rate of the demulsifier is more than 90%. In addition, Fe3O4@G-F has been proven to have good magnetic effects. Under the action of an external magnetic field, Fe3O4@G-F can be recycled and reused in a two-phase system four times, and the demulsification efficiency is higher than 70%. This magnetic nanoparticle demulsifier has broad application prospects for various industrial and environmental processes in an energy-saving manner.