Iron Oxide Research Articles

Useful metals recovery from electronic scraps of headphones – A sustainable approach

The utilization of electronic devices has been consistently increasing each year. In the fiscal year 2020–2021, India handled more than 340,000 tonnes of electronic waste, a significant surge from the 69,414 tonnes recorded in 2017–2018. Over the past four years, there has been a remarkable fourfold increase in the collection and processing of e-waste. This project focuses on e-waste generated from headphones, considering their widespread usage globally. Surprisingly, despite their ubiquity, only 15 % of headphones are recycled, with more than 85 % being discarded as waste. To address this issue, hydrometallurgy treatment is employed to extract valuable metals such as copper and iron. Following this treatment, this research successfully obtained copper carbonate and iron oxide as essential elements. The leached solution undergoes analysis using Atomic Absorption Spectroscopy (AAS). Further characterization through X-Ray Diffraction (XRD) of batteries and magnets aids in identifying the crystalline materials. Additionally, a cost-benefit analysis was carried out, revealing a 57 % and a 39 % profit in copper carbonate and iron oxide extraction respectively and this validates the confirmation of circular economy. Finally, a questionnaire survey was conducted with approximately 192 students, revealing that most headset replacements occur roughly once a year, typically within a budget of around Rs. 500–1000. This strongly indicates a high rate of waste disposal.

Modulating built-in electric field via Bi-VO4-Fe interfacial bridges to enhance charge separation for efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting on semiconductor electrodes is considered to be one of the important ways to produce clean and sustainable hydrogen fuel, which is a great help in solving energy and environmental problems. Bismuth vanadate (BiVO4) as a promising photoanode for photoelectrochemical water splitting still suffers from poor charge separation efficiency and photo-induced self-corrosion. Herein, we develop heterojunction-rich photoanodes composed of BiVO4 and iron vanadate (FeVO4), coated with nickel iron oxide (NiFeOx/FeVO4/BiVO4). The formation of the interface between BiVO4 and FeVO4 (Bi-VO4-Fe bridges) enhances the interfacial interaction, resulting in improved performance. Meanwhile, high-conductivity FeVO4 and NiFeOx oxygen evolution co-catalysts effectively enhance bulk electron/hole separation, interface water’s kinetics and photostability. Concurrently, the optimized NiFeOx/FeVO4/BiVO4 possesses a remarkable photocurrent density of 5.59 mA/cm2 at 1.23 V versus reversible hydrogen electrode (vs RHE) under AM 1.5G (Air Mass 1.5 Global) simulated sunlight, accompanied by superior stability without any decreased of its photocurrent density after 14 h. This work not only reveals the crucial role of built-in electric field in BiVO4-based photoanode during PEC water splitting, but also provides a new guide to the design of efficient photoanode for PEC.

Efficient synthesis of magnetic activated carbon from oak pericarp for enhanced dye adsorption: A one-step approach

This study presents a one-step synthetic method utilizing oak pericarp treated with FeCl3 and ZnCl2 as a precursor for the production of magnetic activated carbon (MAC). Characterization techniques including FTIR, SEM-EDX, TGA, XRD, VSM, BET, and pHpzc confirm the integration of biochar characteristics and magnetic properties of iron oxides in the MAC composite. Batch adsorption tests investigate the adsorption capacity of Rhodamine B (RhB) and Rose Bengal (RB) dyes by MAC under varied conditions, including adsorbent dose, contact time, solution pH, ionic strength, temperature, and initial dye concentration. Optimal adsorption conditions for RhB and RB are identified at pH 2 and 7, with adsorbent doses of 0.75 g/L and 1 g/L, and equilibrium times of 180 min and 120 min, respectively. Adsorption isotherm models (Langmuir, Freundlich, and Temkin) are employed, with the Freundlich model providing the best fit. MAC demonstrates a maximum monolayer adsorption capacity of 198.529 mg.g−1 for RhB and 42.551 mg.g−1 for RB at 20 °C. Kinetic data align with the pseudo-second-order model, and thermodynamic parameters confirm the spontaneous and endothermic nature of the adsorption process. In conclusion, this study successfully synthesizes magnetic biochar with enhanced efficacy in dye adsorption. The one-step method proves efficient for treating industrial dye effluents, as evidenced by batch desorption studies over four cycles, establishing the reusability of the MAC.

Synthesis of Nano-Scale Molecular Iron Oxides as Photo-Catalyst for Molecular Transformations

Synthesis of Nano-Scale Molecular Iron Oxides as Photo-Catalyst for Molecular Transformations

Super paramagnetic iron oxide contrast-enhanced magnetic resonance imaging was useful in differentiating an insulinoma from an accessory spleen: a case report with review of literature.

When a neuroendocrine tumor with abundant blood flow is located in the pancreatic tail, it is difficult to distinguish it from accessory spleen. The patient was a 71-year-old woman who was admitted with impaired consciousness and hypoglycemia, raising suspicion of insulinoma. The selective arterial calcium injection test suggested a lesion in the pancreatic tail. Contrast-enhanced computed tomography and magnetic resonance imaging (MRI) showed a mass in the splenic hilum; however, its continuity with the pancreas was unclear. Contrast-enhanced MRI using super paramagnetic iron oxide (SPIO) showed no SPIO uptake in the splenic hilar mass. SPIO contrast-enhanced MRI is considered useful for differentiating pancreatic endocrine tumors from paraspleen tumors.

The influence of the polyvalent nanodisperse iron oxide and quercetin composition on the women's psycho-emotional state and cognitive function under war stress

Chronic psycho-emotional stress has a permanent negative impact on the psycho-emotional state and cognitive function of the population of the Kyiv region. The purpose of the study was to find out the effect of the course application of the composition of polyvalent nanodisperse iron oxide and quercetin on the psycho-emotional state and cognitive functioning of women who were in conditions of psycho-emotional stress as a result of the Russian-Ukrainian war. The study included 56 women aged 40-74 years who had been in the Kyiv region without permission since the beginning of the Russian-Ukrainian war (February 24, 2022). After the examination, the women were divided into two groups, 28 people each, which did not differ among themselves regarding indicators. The women of the first group took a nanocomposite (dietary supplement "LisoferrinTM") for a month, consisting of polyvalent nanodispersed iron oxide, quercetin and ascorbic acid. Women in the control group took a placebo for a month. The psycho-emotional state was determined using the PLC-5 scale and the Beck depression scale, the Spielberger-Hanin test, and cognitive functions were determined using the Montreal Cognitive Function Assessment Scale (MoCA), the Schulte test, and the reaction speed test. After the course the use of lysoferrin, an improvement in the general condition of the examinees was found, a decrease in body stress, the level of situational and personal anxiety, the level of depression, as well as an increase in the overall score of the Montreal test and a decrease in the time for completing the task in the Schulthei test, which indicates an improvement in mental functions. _________________________________________________________________________________________ Keywords: psycho-emotional state; quercetin; mental capacity

Biomass-derived carbon heterostructure composites modified with magnetic iron oxide for excellent EMW-absorbing materials

With the gradual spread of satellite navigation, broadcasting, and communication technologies, the problem of electromagnetic pollution in C- and Ku-band has increased. Electromagnetic wave (EMW) absorbing materials can effectively mitigate this problem. Here, we report the design of a biomass carbon heterostructure for the absorption of EMWs. This design takes advantage of the natural fiber mesh structure of the loofah and the voids, veins, and basal tissues surrounding the fibers. The material is then carbonized to create a radar antenna-like structure of fibers and nanosheets. This improves the material's conductive loss. In addition, modification with magnetic iron oxide in loofah sponges improves the impedance matching of the materials, enhances the magnetic loss, and increases the heterogeneous interface. We found that the maximum effective absorption frequency range of the prepared EMW-absorbing materials is 3.80 GHz, which is mainly concentrated in the C-band and Ku-band, and its maximum RLminvalue is −59.20 dB. The material's ability to absorb EMWs was also verified by simulating the radar cross section (RCS). In conclusion, this work develops a green and efficient composite material for absorbing EMWs and provides new design ideas for the development of EMW-absorbing materials.

Directional growth of iron oxide nanowires on a vicinal copper surface

Single-crystal magnetic nanostructures with well-defined shapes attract lots of interest due to their potential applications in magnetic and spintronic devices. However, development of methods allowing controlling their mutual crystallographic and geometric orientation constitutes a significant scientific challenge. One of the routes for obtaining such structures is to grow the materials epitaxially on naturally-structured supports, such as vicinal surfaces of single-crystal substrates. Iron oxides are among the most well-known magnetic materials which, depending on the phase, may exhibit ferro/ferri- or antiferromagnetic ordering. We have grown iron oxide nanowires on a Cu(410) single-crystal substrate faceted with molecular oxygen. Scanning tunneling microscopy and low energy electron diffraction revealed that the oxide grows in the [111] direction, along the step edges of the substrate and rotated by ±15° with respect to the [010] direction of copper atomic terraces (so that the the growing elongated structures are orientated parallel to each other). Notably, x-ray photoelectron spectroscopy confirmed that the nanowires represent the ferrimagnetic γ-Fe2O3 (maghemite) iron oxide phase, while micromagnetic simulations indicated that the wires are single-domain, with the easy magnetization axis orientated in-plane and along the long axis of the wire.

Biogenic magnetic nanocomposite of hydroxyapatite and dextran: synthesis, characterization, and enhanced removal of 2,4-D from aqueous environment.

In this study, a biogenic magnetic nanocomposite, HAP@DEX@MNP, using hydroxyapatite from eggshell waste and dextran was developed to efficiently remove 2,4-D from aqueous solutions. The magnetic nano biocomposite underwent rigorous characterization using a comprehensive suite of analytical techniques, including FTIR, XRD, FESEM, EDX, TEM, and VSM. FTIR analysis was used to validate the existence of pivotal functional groups, such as phosphate, carbonyl, hydroxyl, and iron oxide. XRD analysis verified both the crystalline nature of hydroxyapatite and the successful integration of dextran and hematite within the composite structure. FESEM and EDX examinations provided valuable insights into the surface morphology and elemental composition. TEM observations elucidated the existence of nano-sized particles underscoring the unique structural characteristics of the nanocomposite. Batch adsorption experiments were conducted under optimized conditions, highlighting the critical role of pH 2 for efficient 2,4-D removal. The mechanisms driving the binding of 2,4-D to HAP@DEX@MNP were found to encompass diverse interactions, encompassing electrostatic forces, hydrogen bonding, π-π interactions, and van der Waals forces. Adsorption isotherm studies revealed both monolayer and multilayer adsorption, with the Langmuir and Freundlich models fitting well, indicating a maximal adsorption capacity of 217.39µg/g at 25°C. Kinetic investigations supported the pseudo-second-order model for efficient adsorption dynamics, and thermodynamic analysis emphasized the versatility of HAP@DEX@MNP across different temperatures. Importantly, the study highlighted the remarkable regenerative capacity of the nanocomposite using a 0.1M NaOH solution, positioning it as an environmentally friendly option for water treatment. In conclusion, HAP@DEX@MNP holds significant potential for diverse applications in addressing global water treatment and environmental challenges.

Pharmaceutical Quality by Design Approach to Develop High-Performance Nanoparticles for Magnetic Hyperthermia.

Magnetic hyperthermia holds significant therapeutic potential, yet its clinical adoption faces challenges. One obstacle is the large-scale synthesis of high-quality superparamagnetic iron oxide nanoparticles (SPIONs) required for inducing hyperthermia. Robust and scalable manufacturing would ensure control over the key quality attributes of SPIONs, and facilitate clinical translation and regulatory approval. Therefore, we implemented a risk-based pharmaceutical quality by design (QbD) approach for SPION production using flame spray pyrolysis (FSP), a scalable technique with excellent batch-to-batch consistency. A design of experiments method enabled precise size control during manufacturing. Subsequent modeling linked the SPION size (6-30 nm) and composition to intrinsic loss power (ILP), a measure of hyperthermia performance. FSP successfully fine-tuned the SPION composition with dopants (Zn, Mn, Mg), at various concentrations. Hyperthermia performance showed a strong nonlinear relationship with SPION size and composition. Moreover, the ILP demonstrated a stronger correlation to coercivity and remanence than to the saturation magnetization of SPIONs. The optimal operating space identified the midsized (15-18 nm) Mn0.25Fe2.75O4 as the most promising nanoparticle for hyperthermia. The production of these nanoparticles on a pilot scale showed the feasibility of large-scale manufacturing, and cytotoxicity investigations in multiple cell lines confirmed their biocompatibility. In vitro hyperthermia studies with Caco-2 cells revealed that Mn0.25Fe2.75O4 nanoparticles induced 80% greater cell death than undoped SPIONs. The systematic QbD approach developed here incorporates process robustness, scalability, and predictability, thus, supporting the clinical translation of high-performance SPIONs for magnetic hyperthermia.

Comparative analysis of the antimicrobial activity of iron and iron oxide nanoparticles against Trichothecium roseum

Comparative analysis of the antimicrobial activity of iron and iron oxide nanoparticles against Trichothecium roseum

Optimisation of hybrid process to recover zinc from electric arc furnace dust using design of experiment approach

ABSTRACT Recoverable metals like zinc and iron are present in the dust from electric arc furnaces (EAF), a byproduct of the steelmaking process. These metals are mainly present as zinc ferrite (ZnFe2O4), magnetite (Fe3O4), and zinc oxide (ZnO) compounds. ZnO is easily dissolved in either an acidic or an alkaline solution; however, ZnFe2O4 is more difficult to dissolve. Therefore, our earlier paper suggested the thermodynamic analysis of a preliminary caustic-roasting treatment to transform the ZnFe2O4 from EAF dust into more soluble products of ZnO and NaFeO2. Finally, the present study carried out a hybrid process that involved the caustic roasting of EAF dust and a caustic leaching of the roasted product. At first, the effects of caustic-roasting process parameters on zinc-ferrite conversion were studied using the Taguchi method. The implication of Design of Experiment (DoE)-Taguchi analysis and the analysis of variance (ANOVA) shows the optimum caustic-roasting conditions are: roasting temperature of 350 oC, NaOH/ EAF dust molar ratio of 4, and roasting time of 60 minutes. The effect of temperature, reaction time, NaOH concentration, and solid/liquid (S/L) ratio was also examined using the same method in the subsequent caustic-leaching process. Similarly, the analysis shows that maximum Zn dissolution is possible at a NaOH concentration of 6M, a leaching temperature of 40 oC, a liquid-to-solid ratio of 60 ml/g, and a leaching time of 60 minutes. After the hybrid process, the zinc recovery was 83%, while most iron oxides remained in the leach residue.

Tailoring the Magnetic and Hyperthermic Properties of Biphase Iron Oxide Nanocubes through Post-Annealing

Tailoring the Magnetic and Hyperthermic Properties of Biphase Iron Oxide Nanocubes through Post-Annealing

Fenton-like Degradation of Methylene Blue on Attapulgite Clay Composite by Loading of Iron-Oxide: Eco-Friendly Preparation and Its Catalytic Activity.

The continuous discharge of organic dyes into freshwater resources poses a long-term hazard to aquatic life. The advanced oxidation Fenton process is a combo of adsorption and degradation of pollutants to detoxify toxic effluents, such as anti-bacterial drugs, antibiotics, and organic dyes. In this work, an activated attapulgite clay-loaded iron-oxide (A-ATP@Fe3O4) was produced using a two-step reaction, in which attapulgite serves as an enrichment matrix and Fe3O4 functions as the active degrading component. The maximum adsorption capacity (qt) was determined by assessing the effect of temperature, pH H2O2, and adsorbent. The results showed that the A-ATP@Fe3O4 achieves the highest removal rate of 99.6% under optimum conditions: 40 °C, pH = 3, H2O2 25 mM, and 0.1 g dosage of the composite. The dye removal procedure achieved adsorption and degradation equilibrium in 120 and 30 min, respectively, by following the same processes as the advanced oxidation approach. Catalytic activity, kinetics, and specified surface characteristics suggest that A-ATP@Fe3O4 is one of the most promising candidates for advanced oxidation-enrooted removal of organic dyes.

Reusable Magnetite Nanoparticle (Fe3O4 NP) Catalyst for Selective Oxidation of Alcohols under Microwave Irradiation.

Iron oxide nanoparticles (NPs) are nontoxic and abundant materials which have long been investigated as reusable catalysts in oxidation reactions, but their use so far has been hampered by a low selectivity. Here, unsupported iron oxide NPs have been found to successfully catalyze the microwave-assisted oxidation of primary and secondary alcohols to their respective aldehydes and ketones with a high selectivity when N-methylmorpholine N-oxide was used as the terminal oxidant. The crystalline phase and size of the iron-based catalyst have a drastic effect on its activity, with small magnetite (Fe3O4) NPs being the optimal catalyst for this reaction. The nanocatalyst could be easily recovered by magnetoseparation and successfully recycled four times without any need for special pretreatment or reactivation step and with a minimal loss of activity. The subsequent loss of activity was attributed to the transition from magnetite (Fe3O4) to maghemite (γ-Fe2O3), as confirmed by X-ray diffraction, Fourier transform infrared, and X-ray absorption near-edge spectroscopy. The nanocatalyst could then be reactivated by the high-temperature microwave treatment and used again for the microwave-assisted oxidation reaction.

The Effect of Iron Oxide Insertion on the In Vitro Bioactivity, and Antibacterial Properties of the 45S5 Bioactive Glass.

The aging population and increasing incidence of trauma among younger age groups have heightened the increasing demand for reliable implant materials. Effective implant materials must demonstrate rapid osseointegration and strong antibacterial properties to ensure optimal patient outcomes and decrease the chance of implant rejection. This study aims to enhance the bone-implant interface by utilizing 45S5 bioglass modified with various concentrations of Fe3O4 as a coating material. The effect of the insertion of Fe3O4 into the bioglass structure was studied using Raman spectroscopy which shows that with the increase in Fe3O4 concentration, new vibration bands associated with Fe-related structural units appeared within the sample. The bioactivity of the prepared glasses was evaluated using immersion tests in simulated body fluid, revealing the formation of a calcium phosphate-rich layer within 24 h on the samples, indicating their potential for enhanced tissue integration. However, the sample modified with 8 mol% of Fe3O4 showed low reactivity, developing a calcium phosphate-rich layer within 96 h. All the bioglasses showed antibacterial activity against the Gram-positive and Gram-negative bacteria. The modified bioglass did not present significant antibacterial properties compared to the bioglass base.

Rice seeds biofortification using biogenic ıron oxide nanoparticles synthesized by using Glycyrrhiza glabra: a study on growth and yield ımprovement

Iron, a crucial micronutrient, is an integral element of biotic vitality. The scarcity of iron in the soil creates agronomic challenges and has a detrimental impact on crop vigour and chlorophyll formation. Utilizing iron oxide nanoparticles (IONPs) via nanopriming emerges as an innovative method to enhance agricultural efficiency and crop health. The objective of this study was to synthesize biogenic IONPs from Glycyrrhiza glabra (G. glabra) plant extract using green chemistry and to evaluate their nanopriming effects on rice seed iron levels and growth. The synthesized IONPs were analyzed using UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDX) techniques. The UV–Vis peak at 280 nm revealed the formation of IONPs. SEM and TEM showed that the nanoparticles were spherical and had an average diameter of 23.8 nm. Nanopriming resulted in a substantial enhancement in growth, as seen by a 9.25% and 22.8% increase in shoot lengths for the 50 ppm and 100 ppm treatments, respectively. The yield metrics showed a positive correlation with the concentrations of IONPs. The 1000-grain weight and spike length observed a maximum increase of 193.75% and 97.73%, respectively, at the highest concentration of IONPs. The study indicates that G. glabra synthesized IONPs as a nanopriming agent significantly increased rice seeds' growth and iron content. This suggests that there is a relationship between the dosage of IONPs and their potential for improving agricultural biofortification.

Synthesis and characterization of yttrium iron oxide/PPy nanocomposites for supercapacitor application by chemical oxidative polymerization method

ABSTRACT Polypyrrole (PPy)/Yttrium Iron oxide (YIG) nanocomposite was synthesized by the chemical oxidation polymerization method. Yttrium iron oxide is also known as iron yttrium oxide or yttrium iron garnet denoted as YIG (Y3Fe5O12). YIG is a familiar material among the rare earth garnets and is also commonly used in electronic devices. Fourier transform infrared (FT-IR) spectroscopy analysis reveals the strong interaction between PPy and YIG nanoparticles. The crystal structure for the PPy and PPy nanocomposites is observed by X-ray Diffraction (XRD) and the average crystalline size calculated by Scherrer’s formula for PPy/n-YIG is 27.47 nm. Surface morphology of the samples identified by scanning electron microscopy. Optical properties were studied by UV–Vis spectroscopy. From the 2-probe method, AC electrical conductivity for n-YIGPPy is found to be 1.05 × 10−5 S/cm, higher than that of the polypyrrole. The electrochemical performance of PPy and YIG/PPy nanocomposites was observed by cyclic voltammetry (CV). The combination of optical, electrical properties of YIG/PPy nanocomposites suits supercapacitor applications.

Green iron oxide nanoparticles and magnetic nanobiochar: enhancing tomato performance, phytochemicals, and root-knot nematode resistance

BackgroundGreen nanoparticles are considered to be an effective strategy for improving phytochemicals and raising productivity in soil infected by root-knot nematodes. This work aims to understand the characteristics of certain nanomaterials, including non-iron (nFe), green non-iron (GnFe), and green magnetic nanobiochar (GMnB), and the effect of adding them at 3 and 6 mg kg− 1 on phytochemicals and tomato (Solanum lycopersicum) plant growth in soils infected by root-knot nematodes.ResultsSpectroscopic characterization of nanomaterials showed that nFe, GnFe, and GMnB contained functional groups (e.g., Fe-O, S-H, C-H, OH, and C = C) and possessed a large surface area. Application of GMB at 6 mg kg− 1 was the most efficient treatment for increasing the phytochemicals of the tomato plant, with a rise of 123.2% in total phenolic, 194.7% in total flavonoids, 89.7% in total carbohydrate, 185.2% in total free amino acids, and 165.1% in total tannin compared to the untreated soil. Tomato plant growth and attributes increased with increasing levels of soil nano-amendment in this investigation. The addition of GnFe3 and GnFe6 increased the reduction of root galls of root-knot nematodes by 22.44% and 17.76% compared with nFe3 and nFe6, respectively. The inclusion of the examined soil nano-amendments increased phytochemicals and reduced the total number of root-knot nematodes on tomato plants at varying rates, which played a significant role in enhancing tomato growth.ConclusionsIn conclusion, treating tomato plants with GnFe or GMnB can be used as a promising green nanomaterial to eliminate root-knot nematodes and increase tomato yield in sandy clay loam soil.

Phase Separation of ε‐Fe2O3 and BaFe12O19 in a Synthesis Combining Reverse‐Micelle and Sol‐Gel Techniques

Epsilon iron oxide (ε‐Fe2O3) and magnetoplumbite barium ferrite (BaFe12O19) are well‐known hard ferrites. For one synthesis method of ε‐Fe2O3, combining reverse‐micelle and sol‐gel techniques, Ba ions are used to accelerate the formation of nanorod‐shaped ε‐Fe2O3. On the other hand, in synthesis of BaFe12O19 both Ba and Fe ions are used to form the final product. However, the coexistence of these two ferrites has not been reported by any synthesis. Herein, we investigated the effect of Ba ions on the final product for the synthesis combining reverse‐micelle and sol‐gel techniques. At a low Ba ion ratio of [Ba]/[Fe]=0.2, ε‐Fe2O3 nanorods are formed, while at higher Ba ion ratios ([Ba]/[Fe]= 0.4, 1, 2), BaFe12O19 appears. The phase diagram at 1000 °C shows that at a Ba ion ratio of [Ba]/[Fe]= 1, the ratio of ε‐Fe2O3 and BaFe12O19 is almost 1:1. The diagram shows intermediates between these two phases do not form, indicating a phase separation of ε‐Fe2O3 and BaFe12O19. During the sintering process of this synthesis, initially perovskite‐type Ba2Fe2O5 and γ‐Fe2O3 nanoparticles form. Then, in areas where γ‐Fe2O3 nanoparticles are gathered around Ba2Fe2O5 and react, BaFe12O19 is formed, whereas in areas lacking Ba2Fe2O5, ε‐Fe2O3 nanorods are formed within Ba‐ion containing silica glass.