Magnetic Oxide Research Articles

Methotrexate and triformyl cholic acid functionalized magnetic graphene oxide nanocomposite for multi-targeting chemo-photothermal therapy of hepatocellular carcinoma

Methotrexate and triformyl cholic acid functionalized magnetic graphene oxide nanocomposite for multi-targeting chemo-photothermal therapy of hepatocellular carcinoma

Application of a magnetic graphene nanocomposite modified with 5-aminoisophthalic acid amine group for chromium (VI) adsorption from aqueous solutions: kinetic and thermodynamic studies

ABSTRACT Polymer nanocomposites are composite materials that incorporate nanomaterials, such as magnetic graphene oxide (mGO), into a polymer matrix. To enhance its adsorption capacity, the surface of mGO nanoparticles was polymerised by a 5-aminoisophthalic acid amine group (mGO-AIPA) through a simplified co-precipitation method. The structural and morphological characteristics of the synthesised nanoparticles were evaluated through techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Thermogravimetric analysis (TGA), and Vibrating sample magnetometer (VSM). Response surface method (RSM) was used to evaluate the effectiveness of mGO-AIPA nanocomposite in removing chromium (VI) ions by examining variables such as solution of pH, contact time, adsorbent dose and initial concentration. Also, the study of kinetic models, adsorption isotherms and thermodynamic modelling of the process were evaluated. The results found that the mGO-AIPA nanocomposite has the maximum removal of chromium (VI) ions from the aqueous solution by 83.11% in optimal conditions including pH 3.5, contact time of 35 min, an adsorbent dosage of 25 mg g−1 and an initial concentration of 55 mg L−1. The pseudo-second-order kinetic and Langmuir isotherm models had a better fit with the experimental data of adsorption and the maximum adsorption capacity of chromium (VI) the base of the Langmuir model was 90.91 mg g−1. Moreover, the thermodynamic analysis indicated that the process was exothermic and nonspontaneous process, implying that it was energetically unfavourable. These findings suggest that the mGO-AIPA nanocomposite has a high performance as an effectual adsorbent to eliminate chromium heavy metal from an aqueous medium.

Immobilization of L-Asparaginase on biofunctionalized magnetic graphene oxide nanocomposite: A promising approach for Enhanced Stability and reusability

Immobilization of L-Asparaginase on biofunctionalized magnetic graphene oxide nanocomposite: A promising approach for Enhanced Stability and reusability

Recent Advances in the Synthesis of Dihydropyridine and Their Corresponding Fused Systems via Multi‐Component Hantzsch Reaction Using Catalytic Nanomaterials

Abstract1,4‐Dihydropyridines (1,4‐DHPs) represent a versatile class of organic compounds derived from pyridines, recognized for their extensive synthetic applications and significant medical significances. Among the various synthetic methodologies available, the Hantzsch dihydropyridine synthesis is particularly notable as it provides a reliable approach to the production of these compounds. Recent advancements have markedly improved the synthetic pathways leading to Hantzsch dihydropyridines and their derivatives. This review aims to thoroughly examine the recent progress in the synthesis of 1,4‐DHPs, 1,8‐dioxodecahydroacridines (AD), and polyhydroquinolines (PHQ). Emphasis is placed on novel synthetic strategies reported in recent years, specifically those that employ multicomponent reactions involving aldehydes, β‐ketoesters, and ammonium salts. Furthermore, these reactions are catalyzed by various nanocatalysts, including magnetic nanoparticles, nanocomposites, metal oxides, functionalized nanoparticles, and other environmentally friendly nanobiomaterials. The application of nanocatalysts in these processes is underscored by their contributions to structural integrity and activity enhancement, indicative of a paradigm shifts towards more sustainable and efficient synthetic methodologies. This review consolidates and assesses various synthetic routes facilitated by nanocatalysts while elucidating their distinct roles in improving the efficiency and selectivity of 1,4‐DHP synthesis. Hence, this review may pave the way for advancements in Hantzsch reactions by employing nanomaterial catalysts for the sustainable production of 1,4‐DHP derivatives.

Enhanced microwave absorption using multiple heterostructures derived from in-situ grown Sn-metal-organic framework on La-doped Fe3O4

As a representative magnetic oxide absorber, Fe3O4 has attracted considerable research attention owing to its remarkable magnetic saturation strength as well as semiconducting properties. Doping Fe3O4 with La3+ leads to 3d-4f magnetic coupling and ion distribution changes due to the unique electron configuration and large ionic radius of La3+, thereby greatly enhancing the magnetic performance. However, high density, low dielectric loss, and low permeability at high frequencies inhibit the electromagnetic wave absorption (EMWA) performance of ferrites. In this study, stick-shaped Sn metal-organic framework (MOF) is in-situ grown on La3+-doped Fe3O4 using a surfactant. After high-temperature annealing, the SnO2/porous carbon composites derived from Sn-MOF wrap the ferrite, forming a core-shell heterostructure, which not only prevents oxidation but also enhances the EMWA performance. Among the prepared LaxFe3-xO4/SnO2/C (LFSC) samples, LFSC-2 (with LaxFe3-xO4 to Sn-MOF ratio of 1:2) exhibits strong absorption performance with a minimum reflection loss (RLmin) of −44.1 dB. Furthermore, the gradient metamaterial based on LFSC-3 shows ultra-broadband EMWA with an effective absorption bandwidth (RLmin ≤ −10 dB) of 13.17 GHz. In addition, the LFSC-2 sample demonstrates excellent radar stealth capability in the radar cross section (RCS) far-field response, achieving an RCS reduction value of 20.4 dB·m2.

Immobilization of Phospholipase D on Magnetic Graphene Oxide for Efficient Phosphatidylserine Production

Phosphatidylserine (PS) has significant applications in various sectors, such as the medical and food industries. However, its production relies heavily on phospholipase D (PLD), a crucial tool that is hindered by issues like poor stability and irrecoverability. Immobilization presents itself as an effective solution to overcome these limitations. In this study, magnetic graphene oxide (MGO) modified with an amino (NH2) group was synthesized and utilized for PLD immobilization. The activity of the immobilized PLD (MGO-PLD) reached 3062 U/gMGO, with a specific activity of 33.9 U/mgPLD, virtually identical to that of the free PLD. MGO-PLD was utilized to synthesize PS efficiently in a biphasic system. Under optimal conditions, the PS yield reached 18.66 g/L, with a conversion rate of 92.8% and a productivity of 3.11 g/L/h. Notably, MGO-PLD retained an impressive PS conversion rate of 77.4% even after seven repetitive usages. Moreover, MGO-PLD displayed enhanced thermal and pH resistance properties compared to free PLD, alongside augmented storage stability. After an 8-week preservation at 4 °C, its residual activity was maintained at 76.3%. This study provides a sustainable and highly efficient pathway for the biocatalytic synthesis of PS.

Magnetic Mineral Dissolution in Heqing Core Lacustrine Sediments and Its Paleoenvironment Significance

The magnetic parameters within lacustrine sediments serve as invaluable proxies for deciphering the paleoenvironmental and paleoclimatic conditions. However, the dissolution of magnetic minerals can significantly alter detrital magnetic mineral assemblages, thereby complicating their interpretation in paleoenvironmental reconstructions. In an effort to clarify the impact of this dissolution on the grain size of magnetic minerals in lacustrine sediments, we undertook a thorough analysis of the rock magnetic properties on samples from the interval characterized by low ARM (anhysteretic remanent magnetization)/SIRM (saturation isothermal remanent magnetization) values between 140 and 320 ka in the Heqing (HQ) lacustrine drill core, located in Southwest China. Temperature-dependent magnetic susceptibility and FORC diagrams revealed a predominance of single-vortex and pseudo-single domain (PSD) magnetite and maghemite within the sample. When compared to samples from both the glacial and interglacial periods, the high SIRM, elevated magnetic susceptibility, and low ARM/SIRM ratio intervals from 140 to 320 ka suggested a high concentration of magnetic minerals coupled with a relatively low concentration of fine-grained particles in the sediments. The reductive dissolution of the fine-grained magnetic oxides is responsible for the reduction in the fine-grained magnetic particles in this interval. Our findings indicate that pedogenic fine-grained magnetite and maghemite are the first to dissolve, followed by the dissolution of coarser-grained iron oxides into finer particles. This process underscores the complex interplay between magnetic mineral dissolution and grain size distribution in lacustrine sediments, with significant implications for the reliability of paleoenvironmental interpretations derived from magnetic parameters.

Efficient Nanofibrous Electromagnetic Wave Absorber Inspired by Spider Silk Hunting.

With the rapid advancements in wireless communication and radar detection technologies, there has been a significant uptick in the utilization frequency of electromagnetic waves across both civilian and military sectors, consequently generating substantial electromagnetic radiation and interference. These electromagnetic pollutants present a considerable threat to public health and information security. Consequently, materials capable of absorbing and mitigating electromagnetic pollution have garnered significant attention.The nanomaterials with multiple components and various heterogeneous interfaces have been considered as preferred efficient electromagnetic wave (EMW) absorbers. In this work, carbon nanofibers doped with magnetic metal oxide particles (Co/Ni-CNFs) are prepared by electrospinning and heat treatment. In these samples, the minimum reflection loss can reach -40.13dB at 4.6mm, and the widest effective absorption bandwidth is 4.4GHz. The excellent microwave absorption is attributed to the appropriate impedance matching. The electromagnetic parameters of Co/Ni-CNFs are balanced by adjusting the concentration of magnetic metal-organic framework material (MOFs) in the precursor solution. It is believed that this work can provide a reference for developing lightweight, flexible, and robust electromagnetic wave-absorbing materials.

Electronic interaction between d electron-poor and d electron-rich transition metal ions promoted the CO2 capture performance of calcium-based adsorbent

The investigation of intrinsic principles for the more precise design CaO adsorbent with excellent CO2 capture performance by doping metal oxides is of great significance, but has not yet been explored. Herein, we address the critical challenge by systematical evaluation on a series of magnetic bimetallic oxides doped calcium-based adsorbents from the perspective of electronic interaction between d electron-poor and d electron-rich transition metal ions promoting the CO2 capture performance. The Mn, Co, Mo and Ni metal ions with varied d-electron numbers are doped into calcium-based adsorbent, and the results show that the introduction of magnetic bimetallic oxides with d electron-poor and d electron-rich transition metal ions into CaO at the same time can significantly promote the stability of CO2 capture. Taking the (Mn-Co)-codoped samples as an example, the relationship of d electron-poor and d electron-rich transition metal ions synergistic interaction and promoted CO2 adsorption performance is elucidated. The loose flake nanostructures favor the diffusion of CO2 inside the particles, and the uniform distribution of each component effectively ensures the double-exchange interactions. The generation of more oxygen vacancies significantly improves the CO2 affinity for the calcium-based sample. Furthermore, the results of kinetic analysis reveal that the synergistic interaction can reduce the apparent activation energy of carbonation reaction. These insights into the systematical regulation of the double-exchange interaction are expected to provide guidance for the relatively more precise design of the calcium-based adsorbent with high performance of CO2 adsorption.

A comparative study of finite difference approach and bvp4c techniques for water base hybrid nanofluid containing multiple walls carbon nanotubes and magnetic oxide

This study investigates the thermal behaviour of unsteady hybrid nanofluid flow on an infinite vertical plate. The investigation takes into account parameters such as magnetohydrodynamics and radiation effects, as well as the stratified medium. The systems of equations were solved by employing the explicit finite difference approach of Dufort-Frankel method. The main motivation of the study is to compare the performance of water, magnetic oxide, and multi-wall carbon nanotubes as working fluids. Additionally, velocity, temperature, and concentration outlines are visualized through plots, elucidating the fluid behaviour. Tables are provided for the Skin friction, Nusselt number, and Sherwood number, offering comprehensive insights crucial for optimizing performance in engineering applications ranging from thermal management systems to renewable energy technologies. The main finding of this study indicates that the quantitative result reveals that the temperature outline escalates among increasing values of radiation. In contrast, the outlines of a velocity and concentration show a decrease as the values of magnetohydrodynamics increase. In addition, multi-walled carbon nanotubes consume a larger outcome on temperature. A statistical study displays that the thermal stream rate of magnetic oxide-multi-wall carbon nanotubes-water increases from 1.7615 percentages to 7.4415 percentages, respectively, when the volume fraction of nanoparticles rises from 0.01 to 0.05. Future research is important to understanding hybrid nanofluid flows and their applications in thermal engineering systems such as energy systems, nuclear reactors, biomedical applications, electronics cooling, solar thermal systems, chemical processing, and other heat transfer applications where improved thermal performance is crucial.

Synthesis of magnetic zirconium oxide-iron oxide nanoparticles composite using chemical precipitation process for Pb (II) adsorption

The exploration and utilization of natural raw zircon minerals in Indonesia, particularly in Central Kalimantan, remain largely untapped in their potential as high-tech and commercially valuable substances with eco-friendly properties, particularly in water and industrial wastewater treatment. The primary objective of this research is to enhance the development and synthesis of natural raw zircon minerals by converting them into zirconium oxide and integrating them with magnetic nanoparticles. The magnetic nanoparticle composite material for zirconium oxide (MNP@ZrO2) was synthesized using the chemical co-precipitation method. Zirconium and its oxides have gained significant application in water and wastewater treatment in recent years. Through chemical co-precipitation processes (MNP@ZrO2), the natural raw zircon minerals were transformed into zirconium oxides and combined with magnetic nanoparticles due to their exceptional potential as effective adsorbents for anions and cations in water and industrial treatment processes. In the utilization of Scanning Electron Microscopy (SEM), magnetic nanoparticles with a diameter of less than 50 nm emerged on the surface of the zirconium crystals within the magnetic nanoparticle composites. X-ray diffraction (X-RD) analysis indicated that the treatment of zirconium minerals resulted in 11.19% decrease in the Crystallinity Index and a significant reduction of 98% in silica content. By maintaining a pH level of approximately 7 ± 0.2 over 360 min with a stirring rate of 150 rpm, and at ambient temperature, the optimal conditions for Pb (II) adsorption were achieved with the adsorption capacity of 68.98 mg/g using MNP@ZrO2 as adsorbent. The successful synthesis of magnetic zirconium oxide-iron oxide nanoparticles at various pH levels using the chemical co-precipitation process has facilitated a comprehensive assessment of their performance in Pb (II) adsorption.

Unconventional exchange bias and enhanced spin pumping efficiency due to diluted magnetic oxide at the Co/ZnO interface

Exchange bias (EB) is normally created by the interfacial exchange coupling at a ferromagnetic/antiferromagnetic (FM/AFM) interface. FM/AFM interfaces have also been proved to perform enhanced spin angular momentum transfer efficiency in spin pumping (SP), compared with typical FM/nonmagnetic interfaces. Here, we report an unexpected EB and enhanced SP between a ferromagnet and semiconductor. Considerable EB has been observed in Co films grown on ZnO single crystal due to the interface antiferromagnetism of the Zn1−xCoxO (x depends on the Co solubility limit in ZnO) layer. Moreover, SP measurements demonstrate a giant spin pumping efficiency at the Co/ZnO interface with a bump (spin mixing conductance Geff↑↓= 28 nm−2) around the blocking temperature TB ∼ 75 K. The enhanced SP is further confirmed by inverse spin Hall effect measurements and the spin Hall angle θISHE of Zn1−xCoxO is estimated to be 0.011. The bound magnetic polarons with s–d exchange interaction between donor electrons and magnetic cation ions in Zn1−xCoxO play a key role in the formation of antiferromagnetism with giant Geff↑↓. Our work provides a new insight into spin physics at FM/semiconducting interfaces.

Magnetic Graphene Oxide Modified with MOF-199 for Efficient Extraction of Aromatic Amines from Water Samples for Their Determination with Gas Chromatography

A metal–organic framework (MOF-199) nanocomposite was coated on magnetic graphene oxide (MGO) as a sorbent (MGO/MOF-199) and used for the isolation of aromatic amines by magnetic solid-phase extraction (MSPE). The analytes subsequently determined using gas chromatography with a flame ionization detector (GC-FID). The sorbent mass, desorption solvent, extraction time, desorption time, and pH were optimized. The calibration plots demonstrate linear ranges from 0.1 to 500 ng mL−1 with correlation coefficients from 0.9908 to 0.9939. The limits of detection (LOD) were between 0.03 and 0.1 ng mL−1. To evaluate the repeatability, relative standard deviations (RSD) were evaluated for 0.1, 10, and 100 ng mL−1 of the aromatic amines, yielding values from 3.2% to 4.5%. The developed method was employed to extract aromatic amines from tap water, seawater, and spring water. The relative recoveries were from 97.2% to 99.9%.

Profiling the differential phosphoproteome between breast milk and infant formula through a titanium (IV)-immobilized magnetic nanoplatform

Breast milk (BM) fulfills the nutritional needs of infants and sets the standard for infant formula (IF). However, profiling the differential phosphoproteome between BM and IF remains unclear. Herein, a titanium (IV) (Ti4+)-immobilized magnetic nanoplatform (Fe3O4@GO@PDA-Ti4+) was constructed by self-assembly polymerization of dopamine on magnetic graphene oxide, followed by immobilizing Ti4+ through chelation for phosphopeptide enrichment. Fe3O4@GO@PDA-Ti4+ possessed outstanding selectivity (1/1000, a molar ratio of β-casein digests to bovine serum albumin digests) and favorable sensitivity (2.5 fmol/μL), along with rapid magnetic separation. Excellent phosphopeptide capture efficiencies were obtained for BM and IF using Fe3O4@GO@PDA-Ti4+ as an adsorbent coupled with liquid chromatography-mass spectrometry/mass spectrometry. There were 191 and 239 phosphopeptides found in BM and IF, respectively, with 36 phosphoproteins identified in both. However, BM and IF shared only 17 phosphopeptides and 4 phosphoproteins. The variation in the phosphoproteome between BM and IF provides valuable insights into the optimization of IF humanization.

Attachment of ρ-aminobenzene sulphonic acid into magnetic Fe3O4 reduced graphene oxide and its application for sensitive determination of L-tryptophan in milk and banana samples

This paper reports the attachment of p-aminobenzene sulfonic acid on the surface of magnetic Fe3O4-reduced graphene oxide. Different techniques including FTIR, UV, EIS, XRD, and SEM imaging were employed for characterization. The finding indicates the successful attachment of the p-aminobenzene sulfonic acid to the surface. The synthesized material was used to make a carbon paste electrode for the determination of the essential amino acid L-tryptophan (L-Try). EIS and CV characterization of the electrode further confirms the attachment of the acid. Of the different electrode materials used, the p-aminobenzene sulfonic acid attached magnetic Fe3O4 reduced graphene oxide showed very good electrocatalytic activity. The scan rate study showed that the electrode process is an adsorption-controlled one. The prepared electrode material gave a linear curve for 0.001 μM to 10 μM L-Try concentrations, and the limit of detection and limit of quantification were 0.26 nM and 0.78 nM, respectively. Furthermore, the electrode material was employed for the determination of L-Try in a milk and banana sample.

Fabrication of ion imprinted diethylenetriamine pentaacetic acid-polyethylenimine modified magnetic graphene oxide for selective adsorption of Ce(III)

Selective recovery of rare earth elements is essential for both sustainable exploitation of rare earth resources and environmental remediation. Herein, Ce(Ⅲ) imprinted diethylenetriamine pentaacetic acid-polyethylenimine modified magnetic graphene oxide (IIP-DTPA-PEI-MGO) was fabricated for selective adsorption of Ce(Ⅲ). Adsorption efficiency and selectivity performance of IIP-DTPA-PEI-MGO towards Ce(Ⅲ) were evaluated via batch adsorption targeted at single and mixed solution, respectively. Adsorption mechanism was elucidated based on versatile adsorption fittings (isotherms, kinetics, thermodynamics) and spectroscopic tests (XPS, FTIR). Result presents, maximum adsorption efficiency of IIP-DTPA-PEI-MGO for Ce(III) is reached at pH = 5 in 30 min, demonstrating superior efficiency. The maximum mono layer adsorption capacity determined by the Langmuir model is 281.69 mg g−1. After adsorption, 75.65 % of original Ce(Ⅲ) is transferred into Ce(Ⅳ), while 24.35 % remain as Ce(Ⅲ). Furthermore, by virtue of its paramagnetic property, IIP-DTPA-PEI-MGO can be easily recovered for cyclic adsorption, thereby keeping adsorption quantity 90.44 mg g−1 on Ce(Ⅲ) in five consecutive cycles. Owing to ion imprinting sites, IIP-DTPA-PEI-MGO exhibits selectivity coefficient 1.34, 1.69, 2.32, 2.96, 15.24, 10.51 towards Ce(III) for binary solution Ce/La, Ce/Nd, Ce/Eu, Ce/Dy, Ce/Cu, Ce/Cr, respectively. In terms of adsorption mechanism, versatile functional groups O-H, C-N, C-O in IIP-DTPA-PEI-MGO provide heterogeneous affinity for Ce(Ⅲ), inducing chemical adsorption. This work provides a novel approach towards fabricating magnetic bio adsorbent for selective recovery of Ce(Ⅲ).

Mechanochemically assisted synthesis, inversion degree and magnetization of spinel compounds across the (Zn,Mg)Fe2O4 system for flexible smart devices

Magnetic spinel oxides are multifunctional materials used or under consideration for a range of applications across electronics, communication technologies, remediation and health. They can also present high magnetostriction coefficients, and are being investigated as active inorganic fillers in polymer matrix composites for flexible sensors and actuators. However, state-of-the-art materials for these later applications are NiFe2O4- and CoFe2O4-based compositions, and it is necessary to find environmentally-friendly alternatives free of toxic elements that provide comparable responses, ideally biocompatible. This work presents a study of the spinel phases across the (Zn,Mg)Fe2O4 system and of their suitability to be used as magnetic component in hybrid composites. Spinel single phase materials with variable particle size across the submicron range, down to the verge of the nanoscale, have been obtained by mechanochemically assisted synthesis for five selected compositions spanning the whole ZnFe2O4-MgFe2O4 system. Evolution of the crystal lattice and inversion degree (amount of Fe3+ at tetrahedral site) has been obtained from Rietveld refinement of synchrotron X-ray diffraction data, and correlated with the development of magnetic ordering. Ferrimagnetic compositions are identified, among which Zn0.25Mg0.75Fe2O4 stands out for its magnetization characteristics comparable to NiFe2O4. This spinel compound is thus a promising environmentally-friendly candidate for flexible devices, in principle also biocompatible.

Enhanced conversion of a magnetic oxide to metal using induction heating: Application for H2 production

In this study, a C–CoFe2O4 composite is proposed for reduction in an induction heating reactor with a continuous argon flow. An impressive conversion efficiency of 87% is achieved at a maximum temperature of 325 °C in just 8 min without the need for vacuum. The impact of the molar ratio of metal oxide to reducing agent (acetylacetone) is also examined. Results indicate that a 1:1 ratio favours the reduction towards cobalt and iron monoxides, while a 1:3 ratio yields a 31% metal phase. The highest conversion (87%) is seen with a 1:17 ratio, indicating the need for excess reducing agent for effective conversion of CoFe2O4 oxide. The molar ratio influences the induction heating temperature, with the 1:17 ratio having a lower temperature of 325 °C compared to 450 °C for other ratios. These operating temperatures (≤450 °C) are significantly lower than those reported in the literature for carbothermal reduction in an induction reactor (>1700 °C), which often requires vacuum and very high temperatures for high conversion efficiency. The proposed process offers advantages such as high conversion efficiency, fast processing, and simpler operational conditions. Additionally, the metallic phases produced are utilized for H2 production in thermochemical water splitting, showcasing these materials potential for energy generation applications.

Coated and Uncoated Magnetic Iron Oxide Nanoparticles: Toxicity Assessment and Properties of Non Accumulation in Biological Tissues

Background: There are an increasing number of studies on magnetic nanofeeders with multiple applications in agriculture and food processing. Among the magnetic separation oxides, iron oxide has emerged as an indispensable tool in nanoscale differentiation, especially bio-nanoscale. This is attributed to the characteristics of such as size, shape, magnetism and coexistence. Aim of the study: The aim of this study feeding experiment is to prove the non-toxicity of magnetic nano-iron oxides, whether coated when dosed with distilled water or uncoated in milk or distilled water. Subject, materials and methods: Materials: magnetic iron oxide nanoparticles was obtained from SkySpring Nanomaterials (U.S.A.) at a size of 30 nm. Acacia gum (Gum Arabic) is prepared from Thomas Baker (Indian), Sodium hydroxide from Riedel-de Haën (Germany), Potassium phosphate dibasic from CDH (Indian), Potassium phosphate mono basic from HIMEDIA (Indian),Potassium bromide from AVONCHEM(UK), MNPs are characterized by various tools to examine their physicochemical properties. The size of NPs plays a major role in exhibiting different physicochemical properties, and even a small difference in their nanoscale dimensions can alter their properties. Some of the instruments used for their characterization are Atomic Force Microscopy (AFM), Energy Dispersive X-ray Diffraction (EDXD), Field-Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectrometer. Results: After the completion of the experimental period for this study (28 days), the laboratory animals were sacrificed using ether anesthesia. The animals were then dissected using dissection tools to remove these organs. The organs were weighed using a sensitive balance after being washed with 0.9% normal saline solution and dried with filter paper [1][2]. The liver, kidneysamples were collected in pre-labeled plastic containers and preserved in 10% formalin until histological sectioning could be performed. Tissue sections were performed for all organs - liver, kidney and they were placed under a microscope. The results showed no damage to these organs. Conclusion: The findings suggest that both arabic gum-coated and milk-coated magnetic iron oxide nanoparticles, at the tested doses and treatment durations, did not induce observable tissue damage or pathological alterations in the kidneys or liver of the treated rats.

Corn stalk decorated with magnetic graphene oxide as an efficient adsorbent for the removal of cationic dye from wastewater

In this study, an in situ immersion loading method is employed to introduce graphene oxide (GO) nanosheets and hollow copper ferrite nanospheres into the ordered porous structure of alkali-activated corn stalk (CS). This approach facilitates the construction of a novel magnetic three-dimensional composite sponge (GO/CS/CuFe2O4) utilized for the efficient removal of methylene blue (MB) and malachite green (MG) dyes from wastewater samples. In this hybrid adsorbent, the stacking of GO nanosheets is inhibited due to the ordered porous structure of CS, based on which GO nanosheets are well immobilized and dispersed. In addition, the hollow CuFe2O4 nanospheres and GO nanosheets support each other, further reducing the accumulation of GO, and increasing the specific surface area of the adsorbent. The engineered morphology of GO/CS/CuFe2O4 sponges supports the maximum exposure of the active adsorption sites to the dye solution, promoting the adsorption process. Microscopy and surface analyses show that GO/CS/CuFe2O4 sponges have a rich pore structure with the specific surface area of 289.85 m2·g−1, more than 17 times higher than that of CS, significantly improving their adsorption performance for MB and MG. The maximum adsorption capacity of GO/CS/CuFe2O4 for MB and MG is as high as 243.65 and 231.53 mg/g, respectively, superior to those of many other biomass-based adsorbents. The dye adsorption performance of GO/CS/CuFe2O4 can be well described by the Langmuir adsorption isotherm and pseudo-second-order kinetic model, suggesting the existence of strong monolayer chemisorption. The FTIR and X-ray photoelectron spectroscopy (XPS) analyses show that the dye removal mechanisms observed mainly includ π-π interactions, hydrogen bonding, electrostatic interactions and pore filling. In addition, GO/CS/CuFe2O4 sponges exhibit an excellent magnetic behavior (Ms = 49.52 emu/g), enabling the adsorbent to be recycled by the application of a magnetic field. The adsorption capacities of the adsorbent for MB and MG remain 88.6 % and 90.2 % of the initial adsorption capacity, respectively, even after 10 regeneration cycles, showing its excellent reusability performance. Finally, GO/CS/CuFe2O4 is applied for the removal of MB and MG from real aqueous environments comprising the seawater, tap water and wastewater treatment plant effluent, and the removal rates are observed to be over 90 % of that achieved in deionized water. This study provides new concepts for the sustainable utilization of agricultural waste and natural structure of plants to purify dye containing wastewater.