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The present study aimed to synthesize iron oxide nanoparticles loaded with quinine and alkaloids-rich Cinchona officinalis (Peruvian bark) stem bark extract, and further evaluate their cytotoxic effect and apoptosis mechanisms in MCF-7 breast cancer cells. Nanoparticles were prepared by biological reduction of iron oxide with Cinchona officinalis extract, using the green synthesis method. The nanoparticles were characterized by XRD, FT-IR, and UV-vis spectroscopy and transmission electron microscopy (TEM). In vitro cytotoxicity analyses of Cinchona officinalis extract, ferrous oxide, and Cinchona officinalis extract-loaded iron oxide nanoparticles (CO-NPs) were carried out using the MTT test for 24 h and 48 h. We found that CO-NPs reduced the MCF-7 cell viability with IC50 values of 16.2 and 9 µg/mL in 24 h and 48 h, respectively. In addition, CO-NPs were tested with normal hMSCs to determine their toxicity, and we did not find noticeable cytotoxicity. Confocal fluorescent microscopy revealed that CO-NPs efficiently increased the nuclear condensation and chromatin damage in propidium iodide staining; meanwhile, there was decreased mitochondrial membrane potential in CO-NPs-treated MCF-7 cells. In addition, AO-EB staining confirmed the late apoptotic and apoptotic morphology of cancer cells. Further gene expression analysis confirmed that the upregulation of tumor suppressors, Cdkn1A, Prb, and p53 was significantly increased, and inflammatory traits such as TNF-α and Nf-κb were increased in cancer cells treated with CO-NPs. Apoptotic stimulators such as Bax and caspase-3 expression were highly significantly increased, while mdm-2 and Bcl-2 were significantly decreased. Overall, the enhanced cytotoxic potential of the Cinchona officianlis stem bark extract loaded CO-NPs versus free Cinchona officianlis extract might be due to the functional stabilization of bioactive compounds, such as alkaloids, quinine, flavonoids, phenolics, etc., into the iron oxide, providing bioavailability and internalization of cinchona metabolites intracellularly. [ABSTRACT FROM AUTHOR]

Microparticles of iron oxide (MPIOs) are increasingly used for contrast generation in magnetic resonance imaging (MRI). In particular, Dynabeads® MyOne™ Tosylactivated MPIOs have enabled sensitive and targeted molecular imaging, e.g. , to detect vascular inflammation. For the first time we measured the relaxivities as well as the molar susceptibility χ M of these MPIOs at 7 T in agarose gels. They are r1 = 0.69 ± 0.03 s−1/mM, r2 = 220 ± 6 s−1/mM, r2* = 679 ± 14 s−1/mM, and χ M = 0.66 ± 0.05 ppm/mM, when expressed with respect to the iron concentration. These material parameters are essential to optimize MRI protocols and progress toward quantitative imaging. To address the heterogeneous nature of the MPIO distributions over the size of a typical MRI voxel, we coupled the MPIOs to a fluorophore to create a bimodal phantom that can be imaged by both Light Sheet microscopy and MRI. In this phantom, the MPIOs produced contrast similar to that found in vivo. The submicron resolution of Light Sheet microscopy images provided a precise measurement of the MPIO spatial distribution in phantoms also imaged by MRI. MPIO aggregates occupying less than one MRI voxel were responsible for alterations in R2* and magnetic susceptibility χ across several MRI voxels. In these cases, the sum of R2* or χ over the affected MRI volume correlated better with the microscopically determined number of MPIOs. These findings were confirmed with simulations performed in the static dephasing regime. The microscopically determined MPIO distribution was also entered directly into the simulation framework, indicating that the bimodal phantom is a useful tool to test theoretical models against experimental measurements. [ABSTRACT FROM AUTHOR]

In this study, α-Fe2O3/ZnO nanocomposites were synthesized by co-precipitation and solvothermal methods. The morphology, structure, and properties were characterized by FTIR, XRD, FESEM, EDS, and TEM techniques. The XRD patterns showed that the nanocomposite included rhombohedral haematite (α-Fe2O3), hexagonal zincite (ZnO), and cubic franklinite (ZnFe2O4). TEM images revealed the formation of rod-shaped particles with an average diameter of 18 nm and length of 125.82 nm. The quantity of Fe, Zn, and O was obtained to be 12.92%, 9.26%, and 77.82%, respectively. To investigate the effect of the zinc oxide concentration on antibacterial properties, α-Fe2O3/ZnO nanocomposite FZ0.5, FZ1.5, and FZ2.5 were prepared. The antibacterial properties against Staphylococcus aureus, and Escherichia coli bacteria were investigated. α-Fe2O3/ZnO had an efficient antibacterial activity on Gram-positive bacterial strains, and nanocomposites with higher zinc levels demonstrated a more efficient antibacterial activity. The effect of calcination temperature on the antibacterial activity of the sample was also studied. [ABSTRACT FROM AUTHOR]

For the synthesis of polymeric resins, it is of great importance to review the raw materials and the equipment to be used to avoid the presence of compounds that may affect the effectiveness of the polymerization and the characteristics of the plastic to be obtained. Iron oxide is a compound that can be present in reactors after maintenance due to the techniques used and the cleaning of this equipment, and it can affect the characteristics of the resins, reducing their quality. In this study, the presence of FeO in different concentrations was evaluated to determine its effects on the properties and pyrolysis of polypropylene resins by using X-ray refraction to determine the elements of the samples, evaluating thermal degradation by TGA, the variation in molecular weight by measuring the MFI, and the compounds obtained from pyrolysis by chromatography. The results showed that the thermal degradation decreased as the FeO concentration increased, while for the MFI, the relationship was directly proportional. The evaluation of the compounds obtained from pyrolysis showed an increase in the production of alcohols, alkynes, ketones, and acids, and a decrease in alkanes and alkenes, showing that FeO affects the properties of polypropylene and the compounds that are produced during pyrolysis. [ABSTRACT FROM AUTHOR]

Objective(s): Superparamagnetic iron oxide nanoparticles (SPIONs) have been considered promising non-invasive imaging tools in medicine. However, their high surface energy leads to NPs aggregation, while non-targeted SPIONs can cause cytotoxic effects on normal cells. In this work, we evaluated the in vitro potential of polyethyleneimine (PEI)-SPIONs targeted by PNC-27 peptide as a double targeting agent throughout early cancer diagnosis. Materials and Methods: Initially, PEI was conjugated to PNC-27 with HDM-2-binding domain. Then, SPIONs were loaded into PEI-PNC-27 through the ligand exchange method. The physicochemical characteristics of the synthesized NPs were evaluated. The cytotoxicity and targeting efficiency were assayed against HT-29 and CT-26 cell lines along with NIH-3t3 as normal cells by MTT method and Prussian blue staining test, respectively. Results: The mean diameter of synthesized carriers was obtained in the range of 86.6 - 116.1 nm with a positive charge. According to the cytotoxicity results, the binding and uptake abilities of the PNC-27 peptide by cancer cells were significantly higher than that of the NIH-3t3 cells. However, the results were indicative of the more toxic impacts of targeted synthesized NPs against CT-26 cancer cell line when being compared with HT-29 cells, which may be caused by the different cytotoxicity mechanisms of NPs. In addition, the targeted carriers and SPIONs were present inside and around the cells with HDM-2 expression along with only a few non-targeted vectors, while displaying no appearance throughout the normal cell. Conclusion: The results indicated the efficiency of targeted PEI-coated SPIONs for cancer diagnostic applications. [ABSTRACT FROM AUTHOR]

How does the cerium (Ce) doping in ferrimagnetic magnetite (Fe3O4) affect the crosslinking state and kinetics of epoxy crosslinking with amine curing agents? To answer this question, we electrochemically synthesized nanoparticles of Ce–Fe3O4 and characterized them by FTIR, XRD, FE‐SEM, EDX, TEM, and XPS analyses. The presence of Ce atoms in Fe3O4 crystalline lattice increased the surface area and active hydroxyl sites of the prepared magnetic nanoparticles (MNPs) associated with partial shrinkage of molecular lattice. The MNPs uniformly dispersed in epoxy resin and unconditionally tagged epoxy nanocomposites as Excellent cured systems. The effect of lanthanide doping on the cure kinetics of epoxy with amine was explored applying nonisothermal DSC and model‐free kinetic approaches, signifying that Ce–Fe3O4 nanoparticles facilitated epoxy ring opening by intensification of etherification reaction whatever the heating rate. Even at very low loading of Ce–Fe3O4 nanoparticles into the epoxy (0.1 wt.%), the average apparent activation energy significantly decreased by ≈10%. This outcome would highlight the role of crosslinking on the ultimate properties, such as anticorrosive and/or self‐healing characteristics contributed by Ce‐doped nanoparticles once added to epoxy coating formulation. [ABSTRACT FROM AUTHOR]

Achieving an environmentally friendly fuel with respect to minimum sulfur compounds has recently became a significant issue for petroleum refining industries. This paper focuses on investigating oxidative desulfurization (ODS) process for removal of sulfur compounds found in light gas oil (LGO) in a batch reactor (at different reaction temperatures and batch time) using a novel nano-catalyst based on 4% iron oxide (Fe2O3) as an active component. Precipitation and Impregnation methods are used to prepare the nano-gamma alumina (γ-alumina) and to generate the new synthetic homemade nanocatalyst. A mathematical model is formulated for the ODS process to estimate the optimal kinetic parameters within gPROMS package. An excellent consistency with the experimental data of all runs with error less than 5% have obtained. The optimization results display that the new nanocatalyst prepared here is effective in removing more than 97% of the sulfur compounds from LGO resulting in a cleaner fuel. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) is a key energy conversion process, which is critical for the efficient operation of fuel cells and metal–air batteries. Here, we report the significant enhancement of the ORR‐performance of commercial platinum‐on‐carbon electrocatalysts when operated in aqueous electrolyte solutions (pH 5.6), containing the polyoxoanion [Fe28(μ3‐O)8(L‐(−)‐tart)16(CH3COO)24]20−. Mechanistic studies provide initial insights into the performance‐improving role of the iron oxide cluster during ORR. Technological deployment of the system is demonstrated by incorporation into a direct formate microfluidic fuel cell (DFMFC), where major performance increases are observed when compared with reference electrolytes. The study provides the first examples of iron oxide clusters in electrochemical energy conversion and storage. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) is a key energy conversion process, which is critical for the efficient operation of fuel cells and metal–air batteries. Here, we report the significant enhancement of the ORR‐performance of commercial platinum‐on‐carbon electrocatalysts when operated in aqueous electrolyte solutions (pH 5.6), containing the polyoxoanion [Fe28(μ3‐O)8(L‐(−)‐tart)16(CH3COO)24]20−. Mechanistic studies provide initial insights into the performance‐improving role of the iron oxide cluster during ORR. Technological deployment of the system is demonstrated by incorporation into a direct formate microfluidic fuel cell (DFMFC), where major performance increases are observed when compared with reference electrolytes. The study provides the first examples of iron oxide clusters in electrochemical energy conversion and storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stronger Fe-Al interactions decrease FeC x /FeO x ratio but increase Fe 5 C 2 /Fe 7 C 3 ratio. • High content of FeC x is benefit for improving CO 2 hydrogenation activity. • Fe 5 C 2 is more favorable for the formation of heavy hydrocarbons than Fe 7 C 3. • Fe 7 C 3 phase is partially transformed into Fe 5 C 2 during CO 2 hydrogenation. Different iron species exhibit distinct activity and selectivity in CO 2 hydrogenation reaction. Herein, by controlling calcination temperature, Fe-Al interaction in Na promoted Fe-Al catalysts has been regulated, which further leads to various compositions of iron oxide (FeO x) and iron carbides (Fe 7 C 3 and Fe 5 C 2) after CO activation and CO 2 hydrogenation reaction. The phase compositions and structures of Fe-Al catalysts are carefully distinguished by multiple characterizations, including XRD, XPS, MES and TEM, and the reactivity of different phases is studied with the combination of experiments (kinetics, TP and in situ DRIFTS) and Density Functional Theory (DFT) calculations. Our FeAl350 with the highest FeC x content shows the highest CO 2 conversion of 48.2% and the lowest CO selectivity of 10.1%, and FeAl900 with the highest Fe 5 C 2 / FeC x ratio presents the highest C 5+ selectivity of 44.6%. Finally, a correlation between different compositions of iron species with the activity and selectivity of Fe-based for CO 2 hydrogenation to olefins was established. [ABSTRACT FROM AUTHOR]

The scientific community is inclined towards addressing environmental and energy concerns through sustainable means. Conventional processes such as chemical synthesis, involve the usage of environmentally harmful ligands and high tech facilities, which are time-consuming, expensive, energy-intensive, and require extreme conditions for synthesis. Plant-based synthesis is valuable and sustainable for the ecosystem. The use of plant-based precursors for nanoparticle synthesis eliminates the menace of toxic waste contamination. The present review elucidates that the plant based synthesized iron oxide and manganese oxide nanoparticles have tremendous and exceptional applications in various fields such as antimicrobial and antioxidative domains, environmental, electrical and sensing properties. Hence, the literature reviewed explains that plant based synthesis of nanoparticles is an adept and preferred technique. These important transition oxide metal nanoparticles have great applicability in ecological, environmental science as well as electrochemistry and sensing technology. Both these metal oxides display a stable and adaptable nature, which can be functionalized for a specific application, thus exhibiting great potential for efficiency. The current review epitomizes all the latest reported work on the synthesis of iron and manganese oxide nanoparticles through a greener approach along with explaining various significant applications keeping in view the concept of sustainability. [ABSTRACT FROM AUTHOR]

Soils have distinctive chemical, physical, mineralogical and biological properties, which make it possible to differentiate them in different environments and also to test for an association of a particular questioned item with a crime scene. Mineral compositions and structures in the soil clay fraction can reflect a distinct characteristic when analyzed by powerful techniques. In this way, the aim of this study was to compare the discriminative power of Fe‐oxides concentrated clay samples from the same soil class with and without differences in parent material when analyzed using the Rietveld method and two sources of X‐ray diffraction: conventional and high‐resolution synchrotron radiations. Clay samples were Fe concentrated (kaolinite and gibbsite removal) to clarify mineralogical composition of 12 samples from three simulated crime scenes, developed under claystone and granite. By Rietveld refinement, detailed crystallographic data were obtained to discriminate samples according their provenance. By synchrotron radiation, mineral data demonstrated the power of quantitative (crystallite size and minerals contents) and qualitative (identification of majoritarian and accessory minerals) analysis by Rietveld refinement, which provides well‐resolved data able to discriminate samples from different and same geology. The techniques can be applied in other criminal investigations given their potential of discrimination. [ABSTRACT FROM AUTHOR]

In this study, the green synthesis of iron oxide nanoparticles (IONPs) using an aqueous extract of Centaurea cyanus plant, as an appropriate regenerative and stabilising agent, was evaluated. This low-cost adsorbent was then investigated to adsorb a cationic dye such as methylene blue (MB) from an aqueous solution. The various tests such as XRD, BET, FTIR and FE-SEM were applied to characterise the crystalline structure, size, morphology, chemical composition, and properties of nanoparticles. The mean distribution of nanoparticles size was at 24 nm and their shapes were in spherical. Central Composite Design (CCD) under Response Surface Methodology (RSM) was served to model and optimise the MB adsorption from an aqueous solution using the synthesised nanoparticles. Several parameters (such as pH, time, initial concentration of dye and adsorbent dosage) effects on the adsorption process were studied. The optimum MB removal was around 83.96% at MB initial concentration of 90 mg.L−1, pH of 5, adsorbent dosage of 3.6 g.L−1 and time of 93 min. Moreover, isotherm and kinetic of MB adsorption onto the synthesised nanoparticles were carefully investigated. Freundlich isotherm and pseudo-second-order kinetic models could properly legitimise this process. The results showed that the synthesised nanoparticles can be used as an efficient and inexpensive adsorbent for the MB removal. [ABSTRACT FROM AUTHOR]

The present article experimentally investigates the performance of a dielectric cooling fluid (oil Midel 7131) for subsea applications assisted by iron oxide (Fe3O4) or hexagonal boron nitride (hBN) nanoparticles. The experiments are performed in an enclosure in which the two opposite vertical walls are maintained at different temperatures; three temperature differences across the enclosure (i.e., 10 °C, 20 °C and 30 °C) and several concentrations of nanoparticles (i.e., mass% = 0.01, 0.05, 0.1 for Fe3O4 and mass% = 0.01, 0.05, 0.1, 0.5 for hBN) are considered. At first, the effect of the different nanofluid compositions on the viscosity, thermal conductivity and density was preliminarily tested in order to document the effect of nanofluid concentration and temperature. Generally speaking, the characterization revealed a minor effect of the nanoparticle concentration and temperature on the thermo-physical properties, except for the viscosity, which showed a significant reduction with temperature. As for the thermal performance of the heat transfer fluid, the results suggest that, in general, the inclusion of nanoparticles produces changes in the convective heat transfer coefficient that are, basically, within the uncertainty of this variable. For instance, for oil with mass% concentrations between 0.01 and 0.1 of hBN, the maximum gain in terms of heat transfer coefficient was 1.82%, in contrast to 1.28% for the Fe3O4, which arguably can be attributed to the significant impact of the nanoparticles on the viscosity of the Fe3O4. The experimental results are corroborated with a two-dimensional numerical analysis. [ABSTRACT FROM AUTHOR]

HfO2 and Fe2O3 thin films and laminated stacks were grown by atomic layer deposition at 350 °C from hafnium tetrachloride, ferrocene, and ozone. Nonlinear, saturating, and hysteretic magnetization was recorded in the films. Magnetization was expectedly dominated by increasing the content of Fe2O3. However, coercive force could also be enhanced by the choice of appropriate ratios of HfO2 and Fe2O3 in nanolaminated structures. Saturation magnetization was observed in the measurement temperature range of 5–350 K, decreasing towards higher temperatures and increasing with the films' thicknesses and crystal growth. Coercive force tended to increase with a decrease in the thickness of crystallized layers. The films containing insulating HfO2 layers grown alternately with magnetic Fe2O3 exhibited abilities to both switch resistively and magnetize at room temperature. Resistive switching was unipolar in all the oxides mounted between Ti and TiN electrodes. [ABSTRACT FROM AUTHOR]

This study aims to remove arsenic from an aqueous medium by adsorption on a nanocomposite material obtained by the sol–gel method starting from matrices of silica, iron oxide and NaF (SiO2/Fe(acac)3/NaF). Initially, the study focused on the synthesis and characterization of the material by physico–chemical methods such as: X-ray diffraction, FT-IR spectroscopy, Raman spectroscopy, atomic force microscopy, and magnetization. Textural properties were obtained using nitrogen adsorption/desorption measurements. The zero load point, pHpZc, was also determined by the method of bringing the studied system into equilibrium. In addition, this study also provides a comprehensive discussion of the mechanism of arsenic adsorption by conducting kinetic, thermodynamic and equilibrium studies. Studies have been performed to determine the effects of adsorbent dose, pH and initial concentration of arsenic solution, material/arsenic contact time and temperature on adsorption capacity and material efficiency. Three theoretical adsorption isotherms were used, namely Langmuir, Freundlich and Sips, to describe the experimental results. The Sips isotherm was found to best describe the experimental data obtained, the maximum adsorption capacity being ~575 µg As(III)/g. The adsorption process was best described by pseudo-second order kinetics. Studies have been performed at different pH values to establish not only the optimal pH at which the adsorption capacity is maximum, but also which is the predominantly adsorbed species. The effect of pH and desorption studies have shown that ion exchange and the physiosorption mechanism are implicated in the adsorption process. From a thermodynamic point of view, parameters such as ΔG°, ΔH° and ΔS° were evaluated to establish the mechanism of the adsorption process. Desorption studies have been performed to determine the efficiency of the material and it has been shown that the material can be used successfully to treat a real-world example of deep water with a high arsenic content. [ABSTRACT FROM AUTHOR]

Novel magnetic nanohybrids composed of nanomaghemite covered by organic molecules were successfully synthesized at room temperature with different functionalization agents (sodium polystyrene sulfonate, oxalic acid, and cetyltrimethylammonium bromide) in low and high concentrations. Structural, vibrational, morphological, electron energy-loss spectroscopy, magnetic, and Mössbauer characterizations unraveled the presence of mainly cubic inverse spinel maghemite (γ-Fe2O3), whilst X-ray diffraction and 57Fe Mössbauer spectroscopy showed that most samples contain a minor amount of goethite phase (α-FeOOH). Raman analysis at different laser power revealed a threshold value of 0.83 mW for all samples, for which the γ-Fe2O3 to α-Fe2O3 phase transition was observed. Imaging microscopy revealed controlled-size morphologies of nanoparticles, with sizes in the range from 8 to 12 nm. Organic functionalization of the magnetic nanoparticles was demonstrated by vibrational and thermogravimetric measurements. For some samples, Raman, magnetic, and Mössbauer measurements suggested an even more complex core-shell-like configuration, with a thin shell containing magnetite (Fe3O4) covering the γ-Fe2O3 surface, thus causing an increase in the saturation magnetization of approximately 11% against nanomaghemite. Field cooling hysteresis curves at 5 K did not evidence an exchange bias effect, confirming that the goethite phase is not directly interacting magnetically with the functionalized maghemite nanoparticles. These magnetic nanohybrids may be suitable for applications in effluent remediation and biomedicine. [ABSTRACT FROM AUTHOR]

Ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) have been investigated for biomedical applications, including novel contrast agents, magnetic tracers for tumor imaging, targeted drug delivery vehicles, and magneto-mechanical actuators for hyperthermia and thrombolysis. Despite significant progress, recent clinical reports have raised concerns regarding USPION safety related to endothelial cell dysfunction; however, there is limited information on factors contributing to these clinical responses. The influence of USPION surface chemistry on nanoparticle interactions with proteins may impact endothelial cell function leading to adverse responses. Therefore, the goal of this study was to assess the effects of carboxyl-functionalized USPION (CU) or amine-functionalized USPION (AU) (approximately 30 nm diameter) on biological responses in human coronary artery endothelial cells. Increased protein adsorption was observed for AU compared with CU after exposure to serum proteins. Exposure to CU, but not AU, resulted in a concentration-dependent decrease in cell viability and perinuclear accumulation inside cytoplasmic vesicles. Internalization of CU was correlated with endothelial cell functional changes under non-cytotoxic conditions, as evidenced by a marked decreased expression of endothelial-specific adhesion proteins (eg, vascular endothelial-cadherin and platelet endothelial cell adhesion molecule-1) and increased endothelial permeability. Evaluation of downstream signaling indicated endothelial permeability is associated with actin cytoskeleton remodeling, possibly elicited by intracellular events involving reactive oxygen species, calcium ions, and the nanoparticle cellular uptake pathway. This study demonstrated that USPION surface chemistry significantly impacts protein adsorption and endothelial cell uptake, viability, and barrier function. This information will advance the current toxicological profile of USPION and improve development, safety assessment, and clinical outcomes of USPION-enabled medical products. [ABSTRACT FROM AUTHOR]

Short-range-ordered Fe(III) minerals such as ferrihydrite (Fh) are ubiquitous in the environment, are key players in biogeochemical cycling, and sorb trace elements and nutrients. As such, it is important to be able to identify the presence of such minerals in natural samples. Fh is commonly observed to be X‑ray amorphous and cannot be easily analyzed using X‑ray diffraction, meaning that spectroscopic methods such as X‑ray absorption or 57Fe Mössbauer spectroscopy (MBS) are necessary for accurate identification and quantification. Despite decades of research into Fh using MBS, there is a discrepancy in the literature about the exact parameters applicable to the mineral when measured at liquid helium temperature. Fh is frequently fitted with either one, two, or three hyperfine sextets with little interpretation applied to the meaning of each, which is problematic as a one sextet model does not account for the asymmetric lineshape frequently observed for Fh. Here, we address inconsistencies in the fitting of Fh and provide a more standardized approach to its identification by MBS. We present a systematic comparison of diferent fitting methods, notably based on Lorentzian and Voigt functions. We suggest that the most suitable approach to fitting pure Fh at liquid helium temperature is with two sextets (A and B) fitted using an extended Voigt-based function with the ability to apply probability distributions to each hyperfine parameter. 2-line Fh: A (δ = 0.49 mm/s; ε = 0.00 mm/s; Bhf = 50.1 T) and B (δ = 0.42 mm/s; ε = –0.01 mm/s; Bhf = 46.8 T) 6-line Fh: A (δ = 0.50 mm/s; ε = –0.03 mm/s; Bhf = 50.2 T) and B (δ = 0.40 mm/s; ε = –0.05 mm/s; Bhf = 47.1 T). We interpret the two sextets to be due to either diferences in the coordination environment of iron, i.e., in tetrahedral or octahedral sites, the presence of a disordered surface phase, or a combination of both. We hope that provoking a discussion on the use of MBS for Fh will help develop a greater understanding of this mineral, and other short-range ordered iron minerals, which are so important in environmental processes. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the change in the stability of Fe2O3/NdFeO3 nanocomposites when exposed to aggressive media over a long period of time. The main purpose of these studies is to investigate the mechanisms of degradation and corrosion processes occurring in Fe2O3/NdFeO3 nanocomposites, as well as the influence of the phase composition on the properties and degradation resistance. According to the X-ray phase analysis, it was found that the variation of the initial components leads to the formation of mixed composition nanocomposites with different Fe2O3/NdFeO3 phase ratios. During corrosion tests, it was found that the dominance of the NdFeO3 phase in the composition of nanocomposites leads to a decrease in the degradation and amorphization rate of nanostructures by a factor of 1.5–2 compared to structures in which the Fe2O3 phase dominates. Such a difference in the degradation processes indicates the high stability of two-phase composites. Moreover, in the case of an aqueous medium, nanocomposites dominated by the NdFeO3 phase are practically not subjected to corrosion and deterioration of properties. The results obtained helped to determine the resistance of Fe2O3/NdFeO3 nanocomposites to degradation processes caused by exposure to aggressive media, as well as to determine the mechanisms of property changes in the process of degradation. The results of the study of the absorption capacity of Fe2O3/NdFeO3 nanocomposites in the case of the purification of aqueous media from manganese and arsenic showed that a change in the phase ratio in nanocomposites leads to an increase in the absorption efficiency of pollutants from aqueous media. [ABSTRACT FROM AUTHOR]

Introduction: In the last decades, magnetic nanoparticles have been considered and are being studied for employment in tumor therapy and imaging. Also, alongside their utilization in the role of MRI contrast factors, investigations of targeting tumor cells with biomolecules like anticancer drugs, antibodies, and siRNA, the utility of magnetic nanoparticles is evaluated. This preliminary work aimed to investigate the effects of iron oxide NPs on embryo growth and development with an emphasis on brain morphology and teratogenic effects. Methods: After recognizing the air sac with candling, one hundred sixty fertile eggs of the Ross 308 broiler strains were divided into 8 groups (n=20). Group 1 (control) received 0.3 mL serum normal. Groups 2, 3, and 4 received iron oxide nanoparticles as maghemite with doses of 100, 250, and 500 ppm, respectively. Groups 5, 6, 7, and 8 received iron oxide NPs as magnetite with doses of 100, 250, 500, and 2500 ppm, respectively. Twenty days after injections, death day, chicken, brain, liver, heart, bursa of Fabricius, and spleen weights and teratogenic samples were recorded, and brain tissues from all chickens were collected for histological evaluations. Results: The results demonstrated that iron oxide NPs had teratogenic effects such as the lack of formation of abdominal wall muscles and exposing the heart out of the thorax. Also, alterations were observed in the weight ratio of the liver, spleen, and bursa of Fabricius in experimental groups compared to the control group. In the microscopic assessment of the brain tissue, hyperemia, neuronophagia, edema around vessels, necrosis, and vacuolation of neurons were noticeable. Conclusion: It can be concluded that iron oxide NPs affect the growth and development of embryos and can cross the BBB and penetrate the brain tissue by affecting brain morphology. [ABSTRACT FROM AUTHOR]

Background: Therapeutic approaches for acute myeloid leukemia (AML) have remained largely unchanged for over 40 years and cytarabine and an anthracycline (e.g., daunorubicin) backbone is the main induction therapy for these patients. Resistance to chemotherapy is the major clinical challenge and contributes to short-term survival with a high rate of disease recurrence. Given the established efficacy of nanoparticles in cancer treatment, this study was designed to evaluate the anticancer property of our novel nanocomposite in the AMLderived KG1 cells. Materials and Methods: To assess the anti-leukemic effects of our nanocomposite on AML cells, we used MTT and trypan blue assays. Flow cytometric analysis and q-RT-PCR were also applied to evaluate the impact of nanocomposite on cell cycle and apoptosis. Results: Our results outlined that ZnO/CNT@Fe3O4 decreased viability and metabolic activity of KG1 cells through induction of G1 arrest by increasing the expression of p21 and p27 cyclin-dependent kinase inhibitors and decreasing c-Myc transcription. Moreover, ZnO/CNT@Fe3O4 markedly elevated the percentage of apoptotic cells which was coupled with a significant alteration of Bax and Bcl-2 expressions. Synergistic experiments showed that ZnO/CNT@Fe3O4 enhances the cytotoxic effects of Vincristine on KG1 cells. Conclusion: In conclusion, this study sheds light on the potent anti-leukemic effects of ZnO/CNT@Fe3O4 and provides evidence for the application of this agent in the treatment of acute myeloid leukemia. [ABSTRACT FROM AUTHOR]

The coke reduction gasification dephosphorization experiments were conducted on converter slag with FeO contents of 15 %, 20 %, 30 % and 35 %, respectively. Thermodynamic calculations, Scanning Electron Eicroscope(SEM) and Energy Dispersive Spectrometer (EDS) showed that the actual reduction Gibbs free energy of P2O5 was less than that of FeO for the coke reduction converter slag product of P2, and the reactive driving force of P2O5 was greater under high FeO conditions. With the increase of FeO content, the gasification dephosphorization rate showed a trend of increasing first and then decreasing. After gasification dephosphorization, the presence of the Fe phase will adsorb more P elements, so the high FeO content is beneficial to increase the P2O5 activity, which is conducive to the gasification dephosphorization reaction. [ABSTRACT FROM AUTHOR]

This work is devoted to the study of the activity of monometallic (Fe/Al2O3) and bimetallic (Fe-Mo/Al2O3) catalysts supported to carrier γ- Al2O3. It has been discovered that the bimetallic catalyst is more active than the monometallic catalyst in the methane decomposition reaction. The results of the influence of molybdenum oxide on the activity of Fe/Al2O3 catalyst in the methane decomposition reaction in the temperature range 500-850°C have been obtained. It has been determined that the addition of molybdenum oxide in the amount of 5 wt. % of the iron catalyst composition leads to an increase in the catalytic activity of the sample in the reaction of methanedecomposition to hydrogen at relatively low temperatures. Compared to Fe/Al2O3 on the FeMo/Al2O3 catalyst at a reaction temperature of 750°C, methane conversionincreases from 8% to 98%, hydrogen yield from 5% to 57%. The increased field of activity Fe-Mo/Al2O3catalyst in the decomposition of methane to hydrogen compared to Fe/Al2O3 catalysts is due to an increase in the dispersity of the active phases of the catalyst, as well as the formation of an easily reduced Fe2(M4)3 phase, according to XRD, TPR-H2, and BET methods. [ABSTRACT FROM AUTHOR]

The magnetic particles modified with silicon dioxide (SiO2) and amino groups (-NH2), as well as the magnetic particles modified with human serum albumin (HSA) were synthesized using the approaches we developed before and characterized by physico-chemical methods in this study. Plasminogen was chosen as a model protein since plasminogen plays a major role in the fibrinolytic system and plasminogen level correlates with different pathologies and conditions. For the first time it has been carried out qualitative and quantitative assessment of plasminogen nonspecific binding (noncovalent adsorption) by the particles in buffer and plasma solutions. The fibrinolytic activity of plasminogen on the surface of the particles has been measured by the aid of commercially available kits and appeared to be 28–30% of its initial value. Plasminogen desorption from the surface of particles was studied in phosphate buffer with NaCl and ε-aminocaproic acid. Despite nonspecific plasminogen binding is an undesirable process, the data obtained is valuable for further modification of particles for high-specific proteins extraction from biological fluids or transport of plasminogen by the particles. The perspectives of particles modified with SiO2 and –NH2, and particles modified with HSA for isolation of protein analytes and their quantitative assessment thereafter have been discussed. [ABSTRACT FROM AUTHOR]

• Co 2 O 3 and CeO 2 were doped in Fe 2 O 3 as anode material of Lithium-ion battery. • The cobalt and cerium oxides doping was beneficial to particles refinement. • Co 2 O 3 and CeO 2 doping could significantly improve the electrochemical stability. Lithium-ion batteries offer several advantages, including high specific energy, extended lifespan, portability, and environmental friendliness. Transition metal oxides are attractive candidates for negative electrode materials due to their higher theoretical specific capacity. To address issues related to poor stability and volume expansion, cobalt trioxide and cerium oxide were introduced as dopants in iron oxide. This study involved the preparation of Co 2 O 3 -Fe 2 O 3 and CeO 2 -Co 2 O 3 -Fe 2 O 3 composites, followed by structural characterization and investigation of their electrochemical properties. The doping of cobalt and cerium oxide proved advantageous in refining particle size. Notably, 1% Co 2 O 3 -Fe 2 O 3 particles displayed uniform sizing and tight binding. Additionally, the sample containing 0.05% CeO 2 exhibited the smallest particle size and a more homogeneous distribution. Furthermore, cobalt and cerium oxide doping significantly improved electrochemical stability. The discharge capacity of 1% Co 2 O 3 -Fe 2 O 3 and 0.05% CeO 2 -1% Co 2 O 3 -Fe 2 O 3 after undergoing 100 constant-current charge and discharge cycle respectively remained at 553.17 mAh/g, 698.57 mAh/g. As a negative electrode material in lithium-ion batteries, the composite oxide 0.05% CeO 2 -1% Co 2 O 3 -Fe 2 O 3 demonstrated superior reversibility and stability during the process of lithium-ion insertion and removal, while also exhibiting low contact resistance and charge transfer resistance. [ABSTRACT FROM AUTHOR]

This work presents a magnetic purification method of human erythrocyte Acetylcholinesterase (EC 3.1.1.7; AChE) based on affinity binding to procainamide (Proca) as ligand. Acetylcholinesterase is an acetylcholine-regulating enzyme found in different areas of the body and associated with various neurological disorders, such as Parkinson, Alzheymer and Amyotrophic Lateral Sclerosis. AChE from human erythrocyte purification has been attempted in recent years with low degree of purity. Here, magnetic nanoparticles (MNP) were synthesized and coated with polyaniline (PANI) and procainamide (PROCA) was covalently linked to the PANI. The extracted human erythrocyte AChE formed a complex with the MNP@PANI-PROCA and an external magnet separated it from the undesired proteins. Finally, the enzyme was collected by increasing the ionic strength. Experimental Box-Behnken design was developed to optimize this process of human erythrocyte AChE purification protocol. The enzyme was purified in all fifteen experiments. However, the best AChE purification result was achieved, about 2000 times purified, when 100 mg of MNP@PANI-PROCA was incubated for one hour with 4 ml hemolysate extract. The SDS-PAGE of this preparation presented a molecular weight of approximately 70 kDa, corroborating with few previous studies of AChE from erythrocyte purification. • Acetylcholinesterase dysregulation is associated with several neurological diseases and could be useful to a possible biomarker. • Iron Magnetic Particles revested with polyaniline (PANI) were synthesized using procainamide as a specific ligand. • Hemolysate with Erythrocyte AChE was exposed to MNP@PANI-Proca, washed to remove unbound proteins by magnetic field and AChE was leached under high ionic strength. • Purification was optimized to obtain purified enzyme up to 2,000 times higher and a yield up to 400%. [ABSTRACT FROM AUTHOR]

The formation causes and oxidation behaviour of two types of small-sized and irregular morphological surface cracks on S355 hot-rolled thick plate were investigated. The study employed surface pickling, microstructure analysis and inclusion observation to characterise the cracks. It was observed that the surface morphology of two types of cracks exhibited similarities, while their subsurface morphology differed. The Type-A cracks displayed a bulge shape with a rounded tail, while the Type-B cracks had a V-shaped morphology with a slender tail. The Type-A cracks predominantly consisted of FeO. The surface part of the Type-B cracks contained unusual large-sized carbon particles and Al2O3 inclusions, and the iron oxides within the subsurface part followed the sequence of FeO–Fe2O3–Fe from the centre of the cracks to the steel matrix. It was observed that the Type-A cracks originated from subsurface bubbles in the continuous casting slab, which deformed and developed into surface cracks during the rolling process. The iron oxide inside these cracks was formed through a single oxidation process, and the bulge shape in the subsurface part was a distinguishing characteristic. The Type-B cracks were attributed to surface microcracks on the continuous casting slab, which were linked to the presence of unusual large-sized inclusions. The iron oxides within these cracks underwent two oxidation processes. The subsurface morphology and oxide characteristics are the significant features to identify these small-sized and irregular morphological cracks. [ABSTRACT FROM AUTHOR]

The conductivity spectra of the iron oxide Ba 0.25 Sr 0.25 Fe 0.25 O 4 revealed that sample exhibits a semi-conductor behavior within the temperature and frequency. Based on the direct current analysis, charge carrier transport was assisted by a disorder energy below θ D / 4. For θ D / 4 ≤ T ≤ θ D / 2 , electrical conductivity was attributed to the contribution of the Mott-VRH mechanism. However, for T ≥ θ D / 2 , conduction phenomena were supported by the thermal activation of the small polaron hopping mechanism. At higher frequencies, the electrical characteristics of our sample were clarified through the application of a superlinear power law. The contributions of different conduction processes were predicted using temperature dependent frequency exponents. The hopping energy was found to decrease as the frequency increased, a trend that can be linked to variations in the polaron radius. The impedance results validate the involvement of the resistive grain boundary in the electrical properties and indicate the presence of multiple electrical relaxation phenomena in the Ba 0.25 Sr 0.25 Fe 0.25 O 4 sample. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prepared Shell-Fe/ZnO composite photocatalyst through high-temperature annealing. • Shell-Fe/ZnO catalyst exhibited excellent removal efficiency with structural stability and reusability. • Developed of sustainable, highly efficient, and recyclable catalysts. In this work, a solvothermal approach was employed to load Fe and Zn elements onto processed diatom frustules, and Shell-Fe/ZnO composite photocatalyst was prepared through high-temperature annealing. The prepared Shell-Fe/ZnO composite demonstrated a degradation efficiency of 96.56 % towards TC-HCl within 120 min. Shell-Fe/ZnO was characterized using TGA, XRD, SEM, EDS. TEM, XPS and UV–vis DRS. Furthermore, the study also explored potential influencing factors such as pH, TC-HCl concentration and catalyst dosage. The results indicated that Shell-Fe/ZnO composite exhibits remarkable structural stability and reproducibility in practical applications. Burst experiments demonstrated that both components O 2 - and h + contributed to the decomposition of TC-HCl. The verification of burst experimental results was supported by TOC testing and first-order kinetic modeling. The renewable nature of diatom frustules and the ferromagnetic properties of Fe reduced the production and usage costs of the catalyst, paving the way for the development of sustainable, highly efficient, and recyclable catalysts, thereby providing a novel direction for the photochemical degradation of TC-HCl. [ABSTRACT FROM AUTHOR]

In this study, the influence of temperature (40, 60 and 80 ∘C) and light exposure on the dissolution of ▪ particles in aqueous, oxalic acid (0.45 mol/l) is experimentally investigated. A novel experimental setup, consisting of a vessel with undistorted optical access, allows the recording of dissolving particles using a video system. During post-processing, particles are automatically identified and their size and morphology are determined. Binning particles into discrete time-steps during the reaction yields heavy-tailed distributions characterized by a single parameter estimated through a maximum-likelihood estimation of a doubly truncated power-law fit. For the first time, up to three consecutive phases could be identified during the dissolution process of iron oxide particles. The contribution of each phase to the overall dissolution process is determined by a complex interplay between particle fragmentation, different reaction mechanisms and solid product formation. The initial phase is characterized by the fragmentation of larger particles with a more complex morphology, resulting in greater surface area available for reaction. In the second phase, fragmentation is less apparent and the available particle surface area is reduced. The transition to the third phase relies primarily on the supply of short wavelength light, which leads to the formation of a solid product that can increase the tracked particle diameter. • Up to three consecutive phases during iron oxide particle dissolution. • First phase dominated by particle fragmentation leading to increasing surface area. • Second phase dominated by surface area reduction, less by particle fragmentation. • Third phase occurs only at low temperatures and short-wavelength light exposure. • The third phase is characterized by solid product formation. [ABSTRACT FROM AUTHOR]

• Reduced graphene oxide/iron oxide nanocomposites-based humidity sensors exhibit superior sensing capabilities towards varying humidity levels compared to rGO. • The rGO/Fe 2 O 3 NC humidity sensors showed enhanced sensitivity, excellent sensing response, and quick response/recovery time towards different humidity level. • The humidity sensors displayed long-term stability and excellent selectivity towards different %RH levels. For the humidity sensing, rGO/Fe 2 O 3 nanocomposites were synthesized via an ultrasonic-assisted method, utilizing Hummers' and co-precipitation techniques for rGO and Fe 2 O 3 synthesis. XRD analysis confirmed the formation of rGO and rhombohedral Fe 2 O 3 NPs, while SEM revealed varied (rough sheet-like and dense compact) morphologies. UV–VIS spectra indicated characteristic absorption peaks for rGO, Fe 2 O 3 NPs, and their NCs. In addition, FTIR spectra validated graphene oxide reduction and Fe 2 O 3 NPs/NCs formation. Humidity sensing was assessed across 40–80 % RH at varying frequencies (100 Hz-10 kHz), with 100 Hz identified as the optimal frequency due to water molecule polarization limitations at higher frequencies. The rGO/Fe 2 O 3 (70/30) NC exhibited a rapid response recovery time (5 s/10 s) and high sensitivity (2715.541 %), attributed to additional active sites provided by Fe 2 O 3 , enhancing water molecule adsorption and sensor sensitivity. The sensors demonstrated long-term stability and repeatability, showcasing promising potential for humidity sensing applications. [ABSTRACT FROM AUTHOR]

• The solid electrolyte of iron compound powder ingots can enhance battery capacity. • The ferrous chloride will be converted into Fe 8 O 8 (OH) 8 Cl 1.35 during the charge-discharge cycle. • After charging-discharging, an abnormal layer forms at the interface of solid electrolyte and electrode, leading to interface expansion, cracks, and reduced electrode adhesion. This study investigates a Fe/SSE/GF battery. Iron (Fe) as cathode material contains higher electrical capacity and competitive advantages. The solid-state electrolyte (SSE) material is sodium silicate powder mixed with iron compound powders. There are four types of iron compounds: 1) iron oxide, 2) chlorinated/Na-rich iron oxide, 3) Cl-rich iron oxide, 4) ferrous chloride, which are compared with sodium silicate powder. The negative electrode material is graphite film (GF). According to experiments, converting iron into iron oxide or ferric chloride can enhance battery capacity (beyond 200 mAh/g) and cycle life. The reliability of the Fe/SSE/GF battery was assessed by substituting sodium silicate powder with an iron compound electrolyte and adding binder (Polyvinyl Alcohol, PVA) into powder to enhance the performance of Fe/SSE/GF. This experimental research is not only innovative but also represents a significant milestone in the field of solid-state energy storage. [ABSTRACT FROM AUTHOR]

A weak electric field (WEF, 2 mA cm−2) was employed to promote Fe(III)/Fe(II) cycle on goethite-impregnated activated carbon (FeOOH@AC) filled in a continuous-flow column for enhanced Cr(VI) elimination from water. Surficial analysis and Cr species distribution showed that α-FeOOH of 0.2–1 μm was successfully synthesized and evenly loaded onto AC. Electron transfer from WEF to α-FeOOH was facilitated with AC as electron shuttles, thereby boosting Fe(III) reduction in the α-FeOOH. The generated Fe(II) reduced Cr(VI) and the resultant Cr(III) subsequently precipitated with OH− and Fe(III) to form Cr(OH) 3 and (Cr χ Fe 1-χ)(OH) 3. Therefore, the WEF-FeOOH@AC column exhibited a much lower Cr(VI) migration rate of 0.0018 cm PV−1 in comparison with 0.0037 cm PV−1 of the FeOOH@AC column, equal to 104 % higher Cr(VI) elimination capacity and 90 % longer column service life-span. Additionally, under different Cr(VI) loadings by varying either seepage velocities or influent Cr(VI) concentrations, the WEF-FeOOH@AC column maintained 1.0–1.5 folds higher Cr(VI) elimination and 0.9–1.4 folds longer longevity than those of the FeOOH@AC column owing to the interaction between FeOOH@AC and WEF. Our research demonstrated that WEF-FeOOH@AC was a potential method to promote Cr(VI) elimination from water and offer an effective strategy to facilitate Fe(III)/Fe(II) cycle in iron oxides. [Display omitted] • Weak electric field promoted Fe(III)/Fe(II) cycle on FeOOH@AC by transferring cathodic electrons with AC as shuttles. • WEF-FeOOH@AC could effectively eliminate Cr(VI) by adsorption, reduction, and sequestration. • The WEF-FeOOH@AC column also exhibited excellent resistance to shock Cr(VI) loadings. [ABSTRACT FROM AUTHOR]

The unsaturated behavior of permeable reactive barriers (PRB) is a critical component in predicting the removal efficiency through the adsorption of contaminants. This study investigates the framework to estimate the soil water characteristic curve (SWCC) and hydraulic conductivity function (HCF) for iron oxide-coated sand (IOCS) and zeolite, which are common materials used in PRBs. A multistep outflow (MSO) experiment was performed and the results of the MSO experiment were used to optimize associated parameters in Kosugi's SWCC and HCF. In addition, three scenarios of optimization analysis were investigated to evaluate the best-fitting model for estimating SWCC and HCF. The low root mean square error (RMSE) of fitted parameters indicates the Kosugi model well described the observed suction profiles in MSO experiments. In addition, the lowest RMSE and coefficient of variation suggested the inclusion of the additional parameter β provided the best estimation of the three materials (clean sand, IOCS, and zeolite). The physically reasonable estimation of SWCC and HCF of the three materials from the optimized parameters suggests the proposed framework is a reasonable model for the unsaturated behavior of PRBs. [Display omitted] • Multistep outflow experiment of soils was performed for predicting SWCC. • Iron oxide coated sand and zeolite were selected for PRB applications. • Fitting parameters in Kosugi's SWCC was optimized from MSO experiment. • Reliable prediction of SWCC and HCF of clean sand, IOCS, and zeolite was obtained. [ABSTRACT FROM AUTHOR]

• LIC is made with C-coated iron oxide anode, heteroatom-doped porous carbon cathode. • AC800–3 cathode exhibits 154 F g−1 with 76 % retention after 10,000 cycles at 1 A g−1. • IO550 anode delivers 545 mAh g−1 with 76% capacity retention after 2000 cycles. • LIC exhibits 91 and 65 Wh kg−1 at power densities of 467 and 9350 W kg−1. • LIC retains ∼77% specific capacitance at 1 A g−1 for 5000 cycles. Lithium-ion capacitors (LICs) are promising devices to balance the space between lithium-ion batteries and supercapacitors by merging the battery-type anode and capacitor-type cathode materials in a single device. This work represents a lithium-ion capacitor containing in-situ carbon coating on mix-phase iron oxide from ferrocene as an anode and heteroatom-doping on porous carbon as the cathode. This type of cathode facilitates better wettability and a good contact area between the electrode and electrolyte, leading to a capacitance of 154 F g−1, retaining 76 % capacitance after 10,000 cycles at 1 A g−1. In contrast, the anode half-cell exhibits 545 mAh g−1 at 1 A g−1 and ∼76 % retention in capacity after 2000 cycles. This is because of nano-structuring and mix-phase iron oxide, allowing a conversion-type reaction to store Li-ions at a high rate, and carbon coating provides electronic conductivity and structural strength upon cycling. The full cell LIC demonstrates energy densities of 91 and 65 Wh kg−1 at power densities of 467 and 9350 W kg−1, respectively. This hybrid device can retain ∼77 % specific capacitance at 1 A g−1 for 5000 cycles. Furthermore, this study analyzes the practical application of LICs by evaluating impedance, self-discharge, and leakage current characteristics. [Display omitted] [ABSTRACT FROM AUTHOR]

Iron oxide-based adsorbents showed potential to reach ultra-low phosphorus (P) concentrations to prevent eutrophication and recover P. High affinity, high capacity at low P concentrations (<1 mg L−1), good stability, and reusability of the adsorbent are key factors for economic viability. In this study, nanoparticles of goethite (α-FeOOH), a highly stable phase, have been synthesized with increasing Zn2+-doping, 0–20 %at. Zn/Fe, to manipulate the surface properties, following the results of a previous work. Mössbauer spectroscopy showed preserved goethite phase and increased point of zero charge (pzc) at low Zn-doping percentages, while at higher percentages (>5%at.) co-existing phases with increased specific surface area formed. Low concentrations (0.1–10 mg L−1) batch adsorption tests showed increased P removal per unit mass with increasing doping. However, the highest pzc, affinity and P removal per unit area were observed for the 5%at. doped sample, suggesting this dopant concentration to provide the most effective surface. A regeneration test, performed at a lower pH than usual, showed preserved, even improved P desorption with increasing doping. Mössbauer spectroscopy showed that the nanoparticle phase and composition, up to 5%at., doping was preserved throughout the process. These results are promising to develop a stable effective Zn-doped goethite-based adsorbent for P recovery at ultra-low concentrations. [Display omitted] [ABSTRACT FROM AUTHOR]

• Nb5+-doped γ - Fe 2 O 3 were synthesized by sol–gel method. • As the Nb doping increases (≥3.8 at.%), the transformation from γ - Fe 2 O 3 to α-Fe 2 O 3 was suppressed up to 600 °C. • At elevated temperature of 700 °C, γ - Fe 2 O 3 went through full transformation to α-Fe 2 O 3 by expelling large amount of Nb to the surface of α-Fe 2 O 3 forming FeNbO 4. Nb5+-doped γ - Fe 2 O 3 was synthesized by sol–gel method followed by calcination at various temperatures from 200 to 700 °C, analyzed using Powder X-ray Diffraction (PXRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS) and Mössbauer Spectroscopy. PXRD results show the formation of γ - Fe 2 O 3 at 300 °C and it begins to transform to α-Fe 2 O 3 at 350 °C for pure and 2 at.% Nb-doped samples. As the Nb doping increases (≥3.8 at.%), the transformation was suppressed up to 600 °C. TEM EDS confirms the incorporation of Nb to γ - Fe 2 O 3 lattice in 9.1 at.% Nb sample calcined at 500 °C. At elevated temperature of 700 °C, γ - Fe 2 O 3 went through full transformation to α-Fe 2 O 3 by expelling large amount of Nb to the surface forming FeNbO 4. TEM EDS confirms the compositional change during this process with reduced Nb content in α-Fe 2 O 3 and Nb-rich nanoparticle on the surface of α-Fe 2 O 3. Superparamagnetic properties were observed for Mössbauer spectra when the Nb doping increased, which is caused by decreased particle size. The slight increase in internal magnetic field also indicated the transformation from γ - Fe 2 O 3 to α-Fe 2 O 3. High Nb doping with 20 and 40 at.% shows the formation of FeNbO 4 at lower temperature where limited or almost no Nb substitution in α-Fe 2 O 3 was detected by EDS. [ABSTRACT FROM AUTHOR]

Flexible supercapacitors (SCs) are pivotal in the development of wearable and portable electronic devices because of their exceptional power density, high charge/discharge rates, extended cycle life, lightweight, and flexibility. Graphene (G)-based macroscopic materials, such as one-dimensional fibers, two-dimensional films, and three-dimensional aerogels, exhibit a large specific surface area, low mass, excellent flexibility, and high conductivity. These properties make them highly suitable for use as flexible electrode materials in SCs. However, the low energy density of G-based materials hinders their application in certain fields. Iron oxide (Fe 2 O 3) has garnered considerable attention as a negative electrode material because of its low cost, high theoretical capacity, and environmentally friendly nature. However, its practical application is limited because of its poor cycling stability, easy agglomeration, and low electrical conductivity. The combination of G with Fe 2 O 3 to form a composite material not only addresses the issues of volume change and agglomeration associated with Fe 2 O 3 , but also establishes a robust conductive network that improves the electrochemical performance of composite electrodes. Therefore, the construction of SCs using Fe 2 O 3 /G composite electrodes has gained considerable research attention in recent years. We present a comprehensive review of the recent progress in the design of Fe 2 O 3 /G composites as electrode materials for flexible SCs. In addition, we discuss the current challenges and future prospects associated with the use of Fe 2 O 3 /G composites in flexible SCs. [Display omitted] • Recent progress in the design of iron oxide/graphene composites as electrode materials for flexible SCs is reviewed. • The fabrication methods are discussed in depth to provide insight into various development strategies. • The design strategies of iron oxide/graphene composites with different dimensions were comprehensively discussed. • Challenges in iron oxide/graphene composites-based flexible supercapacitors development were described. [ABSTRACT FROM AUTHOR]

The creation of iron oxide nanostructures with complementary functions has emerged as a requirement for more efficient preclinical nanoparticle-mediated biological research. The physical and magnetic properties of nanoparticles for certain applications are determined by the particle morphology and size, which are crucial factors. We present a method for producing magnetite (Fe3O4) nanoclusters of uniform size by a simple and cost-effective solvothermal process, utilising oleic acid (OA) as the coordinating ligand. The nanocluster sizes are altered by manipulating the temperature during the solvothermal process. Three separate sets of Fe3O4 nanoclusters are synthesised and characterised. The X-ray diffraction (XRD) spectrum exhibits a singular phase characterised by a cubic spinel structure. The particle sizes in the nano range were verified by FESEM, and the interplanar spacing measured by TEM is consistent with that determined by XRD. The confirmation of nanocluster formation was achieved through the utilisation of FESEM and AFM images. The rising temperature correlates with the creation of nanoclusters. The rise in reaction temperature resulted in an augmentation of the size of the crystallite, the shape of nanocrystals, and a rise in the value of saturation magnetization. A high Ms from the magnetic property study confirmed that all the synthesised materials are superparamagnetic. The favourable magnetic characteristics and biocompatibility of the synthesised nanoclusters allow them suitable for biomedical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe x /ACF adsorption materials were prepared by impregnation and calcination. • Fe 0.03 /ACF-500 presented the optimal adsorption performance of toluene. • The adsorption of Fe 0.03 /ACF-500 due to its surface adsorption and pore filling. To enhance the adsorption performance of activated carbon fiber (ACF) on volatile organic compounds such as toluene, a series of Fe x /ACF adsorption materials were prepared by impregnation and anaerobic atmosphere calcination. The various adsorption effects of Fe x /ACF on toluene under different synthesis conditions were discussed, and both the modified and unmodified adsorption materials were characterized by using N 2 adsorption–desorption isotherms, XRF, XRD, FT-IR, SEM, and XPS etc methods. The results indicated that iron modified ACF demonstrated the optimal adsorption performance when ACF was loaded with 3 % iron and calcined at 500 °C, and it achieved a saturated toluene adsorption capacity of 218.12 mg/g, which was 24 % higher than that of the unmodified sample. And its adsorption process of toluene followed Yoon-Nelson model. The adsorption capacity was maintained at approximately 70 % when four adsorption/desorption cycle tests. The toluene adsorption performance of Fe 0.03 /ACF-500 on toluene mainly involved surface adsorption (such as n-π interaction, and π-π interaction), pore filling, and complexation between the loaded metal iron and toluene. [ABSTRACT FROM AUTHOR]

[Display omitted] • MCGHCOF beads were prepared and used for fluoride adsorption studies. • MCGHCOF beads remove fluoride both in standard and field water. • MCGHCOF beads are regenerable and regenerated upto six cycles. • MCGHCOF beads are providing water with safe fluoride levels. The developed biocompatible materials like covalent organic frameworks (COFs) and hydroxyapatite acquire significant defluoridation capacity (DC). But because of their powder nature, creates column blockage, pressure drop during field investigations and difficult in separation after fluoride adsorption. To address these problems, COFs and hydroxyapatite were fabricated in the usable form of beads using chitosan, gelatin and iron oxide materials as magnetic chitosan–gelatin/hydroxyapatite/covalent organic frameworks (MCGHCOF) bio-beads were developed and it was potentially applied for the removal of fluoride from water. The MCGHCOF bio-beads surface and their properties were described with FTIR, EDAX, SEM and XRD analysis. The adsorption studies were performed under the batch method. The HCO 3 – ion has a vital inhibitory effect on DC and this may be because of the similar ionic size of fluoride and HCO 3 –. The enhanced DC of MCGHCOF beads was found to be 4992 mgF-.kg−1 in 30 min at pH 7. Isotherm experimental data of fluoride adsorption was apt with Langmuir isotherm than Fruendlich and D-R isotherm models. The defluoridation system is endothermic and its spontaneous nature was demonstrated with thermodynamic studies. Kinetic studies of experimental data of fluoride adsorption were well-fitted with pseudo-second-order and intraparticle diffusion. The complexation and electrostatic interaction play a predominant role in fluoride adsorption by MCGHCOF beads. The MCGHCOF bio-beads are stable and are reusable upto six cycles. The collected field water sample was examined using MCGHCOF beads and it reduced the fluoride concentration to the tolerable drinking water threshold as recommended by WHO (1.5 mg L−1). [ABSTRACT FROM AUTHOR]

In this work, we prepared sodium borate glass doped with different amounts of iron oxide (Fe 2 O 3) and samarium oxide (Sm 2 O 3). The effects of replacing Fe 2 O 3 with Sm 2 O 3 on the absorbance, optical band gap, Urbach energy, and radiation shielding parameters were studied. With further additions of Sm 2 O 3 , the optical band gap values increased from 2.50 to 2.67 eV, while Urbach energy values decreased from 0.49 to 0.42 eV. Further, we explored the effect of sunlight on the absorbance, optical band gaps, and Urbach energy at 90 min of irradiation time. With further exposure to sunlight, the values of the optical band gaps decreased and Urbach energy increased as the exposure time increased from 0 to 90 min. Moreover, the percent of change in absorbance, optical band gap, Urbach energy, refractive index, nonlinear refractive index and third order susceptibility for the glass samples containing the highest concentration of Sm 2 O 3 is insignificant (< 10 %). The small percentage changes in absorbance, optical band gap, and Urbach energy show that the glasses are stable when exposed to sunlight. On the other hand, the inclusion of higher concentrations of Sm 2 O 3 leads to improved radiation shielding capabilities, as seen by the increased values of the mass attenuation coefficient and half-value layer. Herein, the investigated glasses are both more transparent and more effective at shielding radiation; they're prime candidates for use in this field. • With further additions of Sm 2 O 3 , the optical band gap values increased while Urbach energy values decreased. • The absorbance of all glass specimens showed reduced behavior in the ultraviolet (UV) region. • With further exposure to sunlight, the values of the optical band gaps decreased and Urbach energy increased. • The percent of changes in all parameters of the glass sample containing the highest concentration of Sm 2 O 3 & 10 %. • With higher concentrations of Sm 2 O 3 , the increased values of the mass attenuation coefficient and half-value layer. [ABSTRACT FROM AUTHOR]

In aquifers, the sequestration and transformation of organic carbon are closely associated with soil iron oxides and can facilitate the release of iron ions from iron oxide minerals. There is a strong interaction between dissolved organic matter (DOM) and iron oxide minerals in aquifers, but the extent to which iron is activated by DOM exposure to active iron minerals in natural aquifers, the microscopic distribution of minerals on the surface, and the mechanisms involved in DOM molecular transformation are currently unclear. This study investigated the nonbiological reduction transformation and coupled adsorption of iron oxide minerals in aquifers containing DOM from both macro- and micro perspectives. The results of macroscopic dynamics experiments indicate that DOM can mediate soluble iron release during the reduction of iron oxide minerals, that pH strongly affects DOM removal, and that DOM is more efficiently degraded at low rather than high pH values, suggesting that a low pH is conducive to DOM adsorption and oxidation. Spherical aberration-corrected scanning transmission electron microscopy (SACTS) indicates that the reacted mineral surfaces are covered with large amounts of carbon and that dynamic agglomeration of iron, carbon, and oxygen occurs. At the nanoscale, three forms of DOM are found in the mineral surface agglomerates (on the surfaces, inside the surface agglomerates, and in the polymer pores). The microscopic organic carbon and iron mineral reaction patterns can form through oxidation reactions and selective adsorption effects. Fourier transform ion cyclotron resonance mass spectra indicate that both synergistic and antagonistic reactions occur between DOM and the minerals, that the release of iron is accompanied by DOM decomposition and humification, that large oxygen- and carbon-containing molecules are broken down into smaller oxygen- and carbon-containing compounds and that more molecules are produced through oxidation under acidic rather than alkaline conditions. These molecules provide adsorption sites for sediment, meaning that more iron can be released. Microscopic evidence for the release of iron was acquired. These results improve the understanding of the geochemical processes affecting iron in groundwater, the nonbiological transformation mechanisms that occur at the interfaces between natural iron minerals and organic matter, groundwater pollution control, and the environmental behavior of pollutants. • DOM can mediate the release of soluble Fe from the reduction of soil iron oxide minerals. • Adsorption and oxidation of molecules occur on the mineral surface after DOM action. • Conversion of DOM molecules by minerals through decomposition and condensation, etc. • The release of Fe is accompanied by decomposition and humification of DOM. • Simultaneous synergism and antagonism in the reaction of DOM with minerals. [ABSTRACT FROM AUTHOR]

Simultaneously exhibiting both a magnetic response and piezoelectric energy harvesting in magneto-rheological elastomers (MREs) is a win–win situation in a soft (hardness below 65) composite-based device. In the present work, composites based on iron oxide (Fe2O3) were prepared and exhibited a magnetic response; other composites based on the electrically conductive reinforcing nanofiller, graphite nanoplatelets (GNP), were also prepared and exhibited energy generation. A piezoelectric energy-harvesting device based on composites exhibited an impressive voltage of ~10 V and demonstrated a high durability of 0.5 million cycles. These nanofillers were added in room temperature vulcanized silicone rubber (RTV-SR) and their magnetic response and piezoelectric energy generation were studied both in single and hybrid form. The hybrid composite consisted of 10 per hundred parts of rubber (phr) of Fe2O3 and 10 phr of GNP. The experimental data show that the compressive modulus of the composites was 1.71 MPa (virgin), 2.73 (GNP), 2.65 MPa (Fe2O3), and 3.54 MPa (hybrid). Similarly, the fracture strain of the composites was 89% (virgin), 109% (GNP), 105% (Fe2O3), 133% (hybrid). Moreover, cyclic multi-hysteresis tests show that the hybrid composites exhibiting higher mechanical properties had the shortcoming of showing higher dissipation losses. In the end, this work demonstrates a rubber composite that provides an energy-harvesting device with an impressive voltage, high durability, and MREs with high magnetic sensitivity. [ABSTRACT FROM AUTHOR]

Functional oxide materials have become crucial in the continuous development of various fields, including those for energy applications. In this aspect, the synthesis of nanomaterials for low-cost green hydrogen production represents a huge challenge that needs to be overcome to move toward the next generation of efficient systems and devices. This perspective presents a critical assessment of hydrothermal and polymeric precursor methods as potential approaches to designing photoelectrodes for future industrial implementation. The main conditions that can affect the photoanode's physical and chemical characteristics, such as morphology, particle size, defects chemistry, dimensionality, and crystal orientation, and how they influence the photoelectrochemical performance are highlighted in this report. Strategies to tune and engineer photoelectrode and an outlook for developing efficient solar-to-hydrogen conversion using an inexpensive and stable material will also be addressed. [ABSTRACT FROM AUTHOR]

Hydrogen purification by removing CO traces was studied via the preferential CO oxidation (PROX) reaction using highly dispersed Pt catalysts supported on dual oxide FeO x /TiO 2. These catalysts were prepared by the strong electrostatic adsorption (SEA) method by varying the pH of synthesis and the calcination temperature. By measuring the point of zero charge (PZC) of the support components, it was possible to determine the pH in which Pt can be selectively deposited onto one of the support components, obtaining Pt dispersion values above 90%. The selective SEA of a Pt precursor onto the co-support (FeO x) was achieved at a synthesis pH between the PZCs of the support components (i.e., TiO 2 PZC = 5.2 and Fe 2 O 3 PZC = 6.9) by using a Pt anionic complex. The catalytic activity for the PROX reaction, expressed in terms of the CO conversion, O 2 selectivity to CO 2 , apparent activation energy, and turnover frequency, confirmed that the SEA prepared catalysts were active and selective for the PROX reaction. XPS and TPR results of the Pt/FeO x /TiO 2 catalysts showed the formation of Pt-FeO x interfaces, called as (Pt-FeO x) i interfacial sites, which enhanced the stability and catalytic activity for the PROX reaction. The concentration of these sites can be controlled by the synthesis conditions used, mainly pH and to a lower extent the calcination temperature. [Display omitted] • Pt/FeO x /TiO 2 catalysts were prepared by SEA at a pH that ensures a Pt selective deposition onto Fe-based support. • 1 nm Pt crystallites were selectively deposited over FeO x at a pH between the PZCs of the support components. • The formation of (Pt-FeO x) i interfacial sites were detected by XPS, TPR, TEM and operando DRIFTS analyses. • The concentration of (Pt-FeO x) i interfacial sites is affected by the calcination temperature and the synthesis pH. • The concentration of (Pt-FeO x) i interfacial sites was correlated with the activity of Pt–Fe catalysts in the PROX reaction. [ABSTRACT FROM AUTHOR]

In present work, magneto-rheological elastomers (MREs) based on iron oxide (Fe2O3), carbon black (CB) and their hybrid were prepared using room temperature vulcanized silicone rubber (RTV-SR) as host matrix. The rubber composites based MREs were prepared by solution mixing technique. The tests show that the mechanical performance tunes with presence and absence of magnetic field. The mechanical properties such as compressive modulus, tensile strength and fracture strain were higher for hybrid composites than CB or Fe2O3. It was also found that Fe2O3 based MREs specimen shows high magnetic response and stress relaxation than hybrid composites which shows higher mechanical properties. The multi-hysteresis measurement shows that hybrid with higher reinforcing properties exhibit higher heat build-up losses which are a demerit. These demerits can be overcome by improving stress transfer in composite which can be achieved by enhancing interfacial interaction in composite and will be performed in our future work. [ABSTRACT FROM AUTHOR]

In this study, iron oxide nanoparticles coated with porphyrin and functionalized with trastuzumab (ION–PP–TZ) were applied as a new potential probe for magnetic resonance imaging to detect breast cancer cells. This synthesized nanoprobe was applied to breast cancer (MCF-7) cells under both ex vivo and in vivo conditions. The synthesized nanoprobe was administered by systemic injection into C57BL/6 mice. Then, cytotoxicity, T2 relaxation time, image signal intensity, and biodistribution of nanoprobe measurement are performed. At 12 h after injection, it is found that the non-toxic ION–PP–TZ had reduced (83%) T2 relaxation times. After 8 h, the signal intensity of mice treated with ION–PP–TZ was lowered by 67% when compared to the control sample. Moreover, ex vivo results of mice organs at 12 h after treatment had a larger concentration of a specific nanoprobe in tumors of mice killed eight hours after injection. Iron accumulation in the tumor side in a specific group was higher than those of other organs. The developed nanoprobe showed significant MR contrast agent ability on MCF-7 in vivo and ex vivo under different conditions. As a result, ION–PP–TZ has the potential as an MR imaging probe for breast cancer (MCF-7) cell detection. [ABSTRACT FROM AUTHOR]

Iron(II) oxide, wüstite, is the iron oxide with the lowest oxygen content. Under ambient conditions it is metastable for two reasons: (1) it undergoes eutectoid decomposition to Fe and Fe3O4 below ≈570° C, and (2) depending on temperature, it is thermodynamically stable only for very low oxygen partial pressures, down to below 10−20 bar. Hence, for the growth of single crystals from the melt, the growth atmosphere must contain reducing components to keep the oxygen partial pressure on the required low level. With Ar/CO2/CO mixtures this aim can be reached. It is shown experimentally and by thermodynamic calculation, that the grown crystals contain carbon inclusions. Theoretically it is shown that wüstite crystals without carbon inclusions could be grown in humid N2/H2 mixtures. First experiments are presented in this article, but a further adjustment of experimental parameters is required. [ABSTRACT FROM AUTHOR]