Fe3O4 Nanocomposites Research Articles

Enhanced Catalyst Recovery and Photocatalytic Degradation of Rhodamine B and Methylene Blue Using a ZnO/TiO2/Fe3O4 Nanocomposite: Physicochemical Characteristics and Environmental Implications

AbstractA facile wet chemical approach was adopted to synthesize zinc oxide, titanium dioxide, and iron (II, III) oxide, followed by the synthesis of ZnO–TiO2–Fe3O4 nanocomposite via physical mixing. The synthesized nanoparticles were characterized using X‐ray diffraction, UV–visible spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and energy‐dispersive X‐ray spectroscopy to investigate various physical and chemical characteristics of the prepared samples. Furthermore, the catalytic reduction of methylene blue (MB) and rhodamine B (Rh B) dyes was carried out using prepared nanomaterials as catalysts under UV–visible light illumination. It was observed that the degradation efficiency of the nanocomposite was equivalent to or slightly better than TiO2 nanoparticles and higher than ZnO nanoparticles against both dye solutions. Its removal efficiency using an external magnetic field is much higher than that of the constituent nanoparticles, owing to its higher saturation magnetization. So, the obtained results suggest that the produced nanocomposite can be employed as a high‐potential catalyst for reducing organic dyes and pollutants in wastewater treatments.

High-performance ratiometric magnetic electrochemical sensor for acetamiprid detection using Ag@PDA@Fe3O4 nanocomposites

Acetamiprid (AAP) is a renowned neonicotinoid insecticide for swift insect control that is prone to residue in agricultural products and threatens human health. Magnetic electrochemical sensor (MES) was developed for high-precision detection of AAP based on silver nanoparticle (AgNPs) and polydopamine (PDA) modified Fe3O4 nanocomposites (Ag@PDA@Fe3O4). The electrochemical signals generated by AAP hydrolysis and AgNPs oxidation are respectively used as two special signal sources. An increase in AAP concentration led to a proportional increase in the signal from AAP hydrolysis at +0.9 V (IAAP), while the signal from AgNPs oxidation at +0.27 V (IAg) correspondingly decreased. The output signal ΔIAAP/ΔIAg (R2=0.9890) demonstrates a superior linear relationship compared to ΔIAAP (R2=0.9790) or ΔIAg (R2=0.9740) alone. MES demonstrated a broad linear detection range from 0.01 to 2.00 mg L−1 and an impressive limit of detection (LOD, 3S/M) at 3.6 µg L−1. The incorporation of magnetic glassy carbon electrodes (MGCE) significantly mitigates the detachment of nanomaterials. MES has excellent stability and selectivity, and can successfully detect AAP in actual cowpea samples. This study provides pivotal insights into the design of nanomaterial-based ratiometric electrochemical sensors for the sensitive and selective detection of AAP.

Enhanced photocatalytic performance of magnetically reclaimable N-doped g-C3N4/Fe3O4 nanocomposites for efficient tetracycline degradation

The growing environmental challenge posed by the persistence of tetracycline (TC) antibiotics in natural waters is of increasing concern. To address this, there is an imperative need for advanced methods to mitigate TC residues. Herein, we demonstrate the preparation of nitrogen-doped graphitic carbon nitride integrated with magnetic Fe3O4 (N-g-CN/Fe3O4) composites, showcasing narrow band gaps optimized for TC degradation. These advanced materials, conceived through a thermal poly-condensation approach, utilize citric acid and melamine as precursors for nitrogen and g-CN, respectively. These composites exhibit a face-centered cubic architecture, with particle dimensions between 8 to 12 nm and encompassing both meso and microporous structure. The results of the Brunauer–Emmett–Teller analysis indicated specific surface areas of 6.73 m²/g for g-CN, 69.80 m²/g for N-g-CN, 62.55 m²/g for Fe3O4, and 148.32 m²/g for N-g-CN/Fe3O4. These values demonstrate an increase in surface area upon the incorporation of heteroatom of nitrogen and Fe3O4, into the g-CN matrix, thus influence the photocatalytic performance. Under solar light exposure, the synthesized photocatalysts demonstrated photocatalytic activity with a degradation efficiency of 94.16 % within 120 min. Specifically, the N-g-CN/Fe3O4 (22.5 %) composites exhibited remarkable photocatalytic efficiency due to the narrow band gap energy between N-g-CN and Fe3O4, enhanced light absorption in the visible range, and effective charge carrier separation and transportation to the pollutants. N-g-CN/Fe3O4 (22.5 %) composites demonstrated good recyclability (five cycles), magnetic sustainability, and stability for the degradation of TC and emerging pollutants from wastewater using photocatalysts. Similarly, FGCN composites exhibited good recyclability (five cycles), magnetic retrievability, and stability for degrading organic and emerging pollutants from wastewater through photocatalysis. This efficiency can be attributed to the harmonious combination of nitrogen doping, refined surface area, and the natural heterojunction between N-g-CN and Fe3O4.

Investigation of electrical, dielectric, magnetic and electrochemical characteristics of a BaFe12O19/Co0.5Zn0.5Fe2O4 nanocomposite

BaFe12O19 (barium ferrite, i.e., BaF) nanoparticles, Co0.5Zn0.5Fe2O4 (cobalt zinc ferrite, i.e, CZF) nanoparticles and their nanocomposite were synthesized for the investigation of electrical, magnetic, dielectric, and electrochemical properties. The X-ray diffraction (XRD) pattern revealed the formation of hexagonal structure for BaF nanoparticles and cubic structure for CZF nanoparticles with crystallite size of 32.44 nm and 31.30 nm, respectively. Whereas, for nanocomposite, the crystallite size obtained is 34.21 nm were shifting of peaks revealed the formation of nanocomposite. The Fourier transform Infrared (FTIR) spectra revealed the presence of metal-oxygen vibrational peaks for all the samples. The dielectric data revealed the increase in dielectric constant of nanocomposite as compared to pristine CZF whereas, loss reduced for nanocomposite significantly. Single semicircle in Nyquist plot for all the samples revealed the contribution of grain resistance in impedance. The hysteresis loop showed the increase in specific saturation magnetization from 16.963 emu/g to 21.305 emu/g for nanocomposite when compared with pristine BaF. Whereas specific remnant magnetization increased to 10.305 emu/g for nanocomposites. The electrochemical properties presented by Cyclic voltammetry showed the presence of cathodic and anodic peaks which revealed the presence of redox reaction in all samples. The specific capacitance calculated for all samples at different scan rate revealed that a nanocomposite showed highest Cs value 16.43 F/g at 25 mV, whereas it increased to 27.01 F/g, 35.93 F/g and 38.87 F/g with the increase in scan rate to 50 mV, 75 mV and 100 mV, respectively.

Comparative study of optical properties and photocatalytic performance of Cd0.4Mn0.6O nanocomposites incorporated with different metal oxides

The structural, optical, and photocatalytic properties of Cd0.4Mn0.6XO nanocomposites with 50 wt% of X were investigated (X denotes ZnO, SnO, CuO, Al2O3, Fe2O3, NiO, and CoO). The crystal structure of Cd0.4Mn0.6XO nanocomposites is composed of the monoclinic Cd2Mn3O8 phase, along with other individual phases dependent on the type of X dopant. The crystallite sizes are between 11.07 nm for CoO and 23.65 nm for ZnO, whereas the particle sizes are between 9.75 nm for ZnO and 35.61 nm for Fe2O3. The SnO, NiO, and CoO nanocomposites had the highest values of the effective surface area of 29.71, 26.3, and 24.1 m2/g, respectively. The NiO and SnO nanocomposites had the highest and lowest absorbance, respectively, notably at wavelength below 400 nm. SnO, NiO, CuO, and Fe2O3 nanocomposites have the highest values of energy gap (Eg > 2 eV), whereas CoO, ZnO, and Al2O3 nanocomposites have the lowest Eg values (<2 eV). The SnO nanocomposite exhibited the highest values of refractive index, q-factor, lattice dielectric constant (εL), free carrier density (Nm∗), and optical/electrical conductivity when compared to the other Cd0.4Mn0.6XO nanocomposites. Interestingly, the values of εL, and Nm∗ were enhanced to 21.2 and 4.9 × 1057 cm−3g−1 for SnO nanocomposite, followed by NiO and Fe2O3 nanocomposites. The photodegradation efficiency towards methylene blue (MB) using the Cd0.4Mn0.6XO catalysts after 3 h of irradiation equals 97.94, 76.43, 74.43, 71.32, 65.98, 62.86, and 48.55 % for ZnO, NiO, SnO, Fe2O3, Al2O3, CuO and CoO nanocomposites, respectively. The photocatalytic performance of Cd0.4Mn0.6XO catalysts towards MB was compared to earlier investigations and a scavenger test was performed to validate the formation of reactive oxygen species. The features of Cd0.4Mn0.6XO nanocomposites are convenient for light-emitting diodes, solar cells, reduced electronic noise, high-power operation, and water purification.

Energy and exergy assessment of a photovoltaic-thermal (PVT) system cooled by single and hybrid nanofluids

Photovoltaic-thermal (PVT) concept is a novel methodology to lower the PV module temperature and consecutively produce thermal and electrical energies. This study assesses the thermal and electrical advancements of a PVT system using iron oxide (Fe2O3) single nanofluid and titanium oxide-iron oxide (TiO2-Fe2O3) hybrid nanofluid at 0.2 % and 0.3 % concentrations. The PVT energy and exergy efficiencies were presented and analyzed concerning the effect of proposed single and hybrid nanofluids. Study findings disclosed that dispersing 0.3% of TiO2- Fe2O3 nanocomposites into water has enhanced the nanofluid thermal conductivity, improving the Nusselt number by 90.64 %, while Fe2O3 nanoparticles achieved 31.75 %. Furthermore, employing TiO2- Fe2O3-based nanofluid at 0.3 % has enhanced the PVT electrical efficiency by 13 % and, thermal efficiency by 44 % compared to Fe2O3-based nanofluid, which exhibited 12 %, and 33 %, respectively. Besides, the PVT electrical exergy efficiency was augmented by about 13 % using TiO2-Fe2O3-based hybrid nanofluid, against 11 % using Fe2O3 nanofluid. Reversely, the pressure drop was increased by a maximum of 62.9% when TiO2- Fe2O3 was applied due to the raised nanofluid density compared to the reference base fluid. Conclusively, hybrid nanofluid has a superior influence on the PVT performance than single nanofluids. However, further investigations are required to explore cost-effective hybrid nanofluids with a low pressure drop.

Delivery of doxorubicin by Fe3O4 nanoparticles, reduces multidrug resistance gene expression in ovarian cancer cells

BackgroundOvarian cancer is one of the most common malignancy in women with significant mortality rate due to the resistance to chemotherapy drugs. Doxorubicin (DOX) is a chemotropic agent in ovarian cancer treatment. Overexpression of multidrug resistance (MDR) genes, such as ABCB1, in cancer cells after chemotherapy is one of main problems in clinical applications. Here we have compared the efficiency of doxorubicin-loaded (NIPAAM-DMAEMA) Fe3O4 nanocomposite (DOX-NANO) against DOX on ABCB1(MDR1) gene expression in the ovarian cancer cell line. Materials and MethodsThe cell viability of SKOV-3 cells were evaluated by MTT assay. Real Time PCR was used to measure the expression level of MDR1. MTT data were normalized in 10 different attribute weighting models, also to reveal the interaction between DOX, ABCB1, and ovarian cancer genes, Pathway Studio Database (Elsevier) was used. ResultsCell viability of SKOV-3cells was significantly decreased after 24, 48 and 72hours (P < 0.0001) of either DOX with IC50 22.38, 0.61 and 0.072µg/ml or DOX-NANO treatment with IC50 11.54, 1.01, 0.0126µg/ ml respectively. treatment. Notable decrease in the expression of MDR gene, ABCB1, was observed 48hours after treatment with DOX-NANO (P < 0.0001) with 26% in the assessed with control group. Meta-analysis showed the concentration of 10μg/ml variables was the second most significant feature, whereas the concentration of 0.01μg/ml recognized the lowest weights. Also, LGALS3 is an extra cellular receptor with upregulation in ovarian cancer that interacts with ABCB1. ConclusionOur findings highlight the beneficial effects of DOX delivery in ovarian cancer cells by nanocomposite as efficient drug delivery method. DOX-NANO is a promising therapeutic reagent to overcome chemotherapy resistance in ovarian cancer.

Fabrication, evaluation, and mechanism of TPU nanocomposites containing MWCNTs–Fe2O3 hybrid conductive nanofillers for selective VOC sensing applications

AbstractVolatile organic compounds (VOCs) are highly harmful substances that can bring serious harm to the environment and human health. In this work, thermoplastic polyurethane (TPU) conductive nanocomposite sensors for selective gas sensing of VOCs were designed and fabricated using electrospun TPU fibers as templates and MWCNTs–Fe2O3 as conductive hybrid nanofillers through a homogeneous liquid impregnation method. The microstructure of TPU matrix fibers and the TPU nanocomposites, and their gas‐sensitive response performance to various VOCs, were investigated. The formation of MWCNTs–Fe2O3 nanofillers was confirmed by Fourier transform infrared spectroscopy, X‐ray diffraction, and Raman analysis. Field emission scanning electron microscope showed that MWCNTs–Fe2O3 nanofillers were uniformly coated on the surface of TPU, forming effective and complete conductive networks. The average volume resistivity of TPU nanocomposites (containing 4.76 wt% MWCNTs–Fe2O3) was reduced from 1.5 × 1012 Ω·mm in pure TPU matrix fiber to 2.93 × 105 Ω·mm. Gas‐sensitive performance tests with 500 ppm of ether, ammonia, formaldehyde, ethanol, xylene, toluene, benzene vapor, and acetone showed that the response value of TPU/MWCNTs–Fe2O3 nanocomposites to ether was 85.7%, and the resistance ratio of desorption to the initial one was 1.01, which was almost a complete recovery. In addition, the gas response values of TPU nanoconductive composites under different humidity environments show better stability.Highlights Novel TPU composites contain MWCNTs–Fe2O3 conductive nanofillers were proposed. Synthesized TPU nanocomposite fibers by electrospinning and liquid dip methods. TPU nanocomposite sensors combine fast response, selectivity, and repeatability. TPU nanocomposites exhibited high gas‐sensitive response selectivity to ether.

Ultrasonic-aided preparation of poly(vanillin-co-thiophene)/green Fe₃O₄ nanocomposites via solution mixing for methyl orange adsorption and antibacterial applications

This work describes the preparation of novel nanocomposite materials comprising a newly synthesized semiconducting copolymer, poly(vanillin-co-thiophene) (PVTH), blended with different weight proportions (3 %, 6 %, and 9 % by weight) of greenly synthesized magnetite nanoparticles (GFe3O4 MNPs) via solution mixing, assisted by ultrasonic irradiation. PVTH copolymer was synthesized through the polycondensation of vanillin, a bioderived aldehyde, and thiophene, catalyzed by sulfuric acid. GFe3O4 MNPs were prepared via the coprecipitation method with mint extract as an environmentally friendly stabilizer. The physicochemical properties of the prepared samples were investigated by 1H NMR, 13C NMR, FTIR, XRD, UV–vis, TGA, FE-SEM/Eds, AFM, VSM, tauc plot method and the four-points probe measurement. The samples were evaluated for two applications: methyl orange (MO) adsorption from aqueous solutions and antibacterial activities against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus) bacterial strains. The results showed that ultrasound irradiation facilitated the easy preparation of well-dispersed and homogeneous nanocomposites with combined semiconducting and magnetic properties and improved thermal stability compared to the parent PVTH. The most effective nanocomposite for MO removal was the sample containing 9 % GFe3O4 MNPs, whose adsorption behavior followed pseudo-second-order kinetics and Freundlich isotherm. Its maximum adsorption capacity was 103.79 mg g−1. In addition, all samples showed antibacterial action against the tested bacterial strains, with PVTH showing the highest efficacy, followed by PVTH/GFe3O4 nanocomposites.

Harnessing the potential of MOF/Fe2O3 nanocomposite within polypyrrole matrix for enhanced hydrogen evolution

This study investigates the influence of pyrrole concentration and the addition of MIL53(Al)/Fe2O3 nanocomposite on the hydrogen evolution reaction (HER) activity of polypyrrole (PPy) electrocatalysts. Electrodeposition of PPy on a nickel (Ni) substrate was conducted using various pyrrole concentrations ranging from 0.01 M to 0.2 M, followed by evaluation through linear sweep voltammetry (LSV) experiments. Results indicated that PPy synthesized with 0.1 M pyrrole exhibited the highest HER activity, characterized by lower onset potential and higher current density. Additionally, the incorporation of MIL53(Al)/Fe2O3 nanocomposite into PPy coating enhanced electrode performance, evidenced by high charge transfer kinetics. Nyquist diagrams and electrochemical impedance spectroscopy (EIS) analysis confirmed accelerated electron transfer kinetics and lower charge transfer resistance for PPy@MIL53(Al)/Fe2O3 compared to Ni substrate. Despite a lower electrochemical double layer capacitance (Cdl), PPy@MIL53(Al)/Fe2O3 demonstrated enhanced catalytic activity, underscoring the importance of electrode morphology and active site characteristics. Furthermore, stability tests revealed consistent performance of PPy@MIL53(Al)/Fe2O3 over prolonged electrolysis periods, highlighting its potential for practical applications in hydrogen generation.

Synthesis and Antimicrobial Activity of (E)-1-Aryl-2-(1H-tetrazol-5-yl)acrylonitrile Derivatives via [3+2] Cycloaddition Reaction Using Reusable Heterogeneous Nanocatalyst under Microwave Irradiation.

The magnetically recoverable heterogeneous Fe2O3@cellulose@Mn nanocomposite was synthesized by a stepwise fabrication of Mn nanoparticles on cellulose-modified magnetic Fe2O3 nanocomposites, and the morphology of the nanocomposite was characterized through advanced spectroscopic techniques. This nanocomposite was investigated as a heterogeneous catalyst for the synthesis of medicinally important tetrazole derivatives through Knoevenagel condensation between aromatic/heteroaromatic aldehyde and malononitrile followed by [3+2] cycloaddition reaction with sodium azide. Thirteen potent (E)-1-aryl-2-(1H-tetrazol-5-yl)acrylonitrile derivatives are reported in this paper with very high yields (up to 98%) and with excellent purity (as crystals) in a very short period (3 min @ 120 W) using microwave irradiation. The present procedure offers several advantages over recent protocols, including minimal catalyst loading, quick reaction time, and the utilization of an eco-friendly solvent. Furthermore, the synthesized (E)-1-aryl-2-(1H-tetrazol-5-yl)acrylonitrile derivatives (4b, 4c, and 4m) are shown to have excellent resistance against various fungal strains over bacterial strains as compared to the standard drugs Cefixime (4 μg/mL) and Fluconazole (2 μg/mL).

The Structural, Magnetic, and Electrochemical Properties of Composite PAni/Co&lt;sub&gt;0.2&lt;/sub&gt;Mn&lt;sub&gt;0.8&lt;/sub&gt;Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;

The current work concerns preparing cobalt manganese ferrite (Co0.2Mn0.8Fe2O4) and decorating it with polyaniline (PAni) for supercapacitor applications. The X-ray diffraction findings (XRD) manifested a broad peak of PAni and a cubic structure of cobalt manganese ferrite with crystal sizes between 21 nm. The pictures were taken with a field emission scanning electron microscope (FE-SEM), which evidenced that the PAni has nanofibers (NFs) structures, grain size 33 – 55 nm, according to the method of preparation, where the hydrothermal method was used. The magnetic measurements (VSM) that were conducted at room temperature showed that the samples had definite magnetic properties. Additionally, it was noted that the saturation magnetization value of PAni/Co0.2Mn0.8Fe2O4 nanocomposite and Co0.2Mn0.8Fe2O4 nanoparticles are maximum saturation magnetization values of (4.7) and (9) emu g−1 respectively. Studying properties of electrochemical which were tested in 1 M of H2SO4 by using the CV cyclic voltammetry analysis, galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS), found the highest capacitance is 596 F/g.

4D printing thermo-magneto-responsive PETG-Fe3O4 nanocomposites with enhanced shape memory effects

In this groundbreaking study, Polyethylene Terephthalate Glycol (PETG)-Fe3O4 nanocomposites were developed for 4D printing, incorporating iron oxide (Fe3O4) nanoparticles into PETG matrix. The research contribution lies in its innovative approach to enhancing the shape memory effect (SME) through thermo-magnetic responsiveness, positioning PETG-Fe3O4 as a revolutionary material in smart additive manufacturing. The composites were synthesized using a melt mixing method, followed by 3D printing into specimens for comprehensive evaluation through dynamic mechanical thermal analysis (DMTA), scanning electron microscopy (SEM), and uniaxial tensile tests. The findings revealed that the incorporation of Fe3O4 nanoparticles significantly boosts the composites’ storage modulus and glass transition temperature, indicative of improved stiffness and thermal properties. Notably, the 15 % Fe3O4 composite emerged as the optimal blend, exhibiting the highest tensile strength and a favourable balance between mechanical integrity and flexibility. A key result was the enhanced SME under both thermal and magnetic stimuli, with recovery efficiency and speed escalating with nanoparticle concentration. This advancement underscores the potential of PETG-Fe3O4 nanocomposites in fabricating smart structures capable of environmental adaptability, paving the way for impacts in biomedical, aerospace, and robotic devices. Through this work, a new paradigm in material functionality for 4D printing has been established, demonstrating the viability of magnetic nanoparticle integration for added smart capabilities.

Green synthesized chitosan-coated iron oxide nanocomposite using Cissus quadrangularis plant extract for antibacterial, antioxidant and anticancer applications

Metal oxide nanoparticles (NPs) have demonstrated their potential to eliminate a wide range of drug-resistant bacterial pathogens and cancer cells in recent years. Iron oxide (Fe3O4) NPs have received significant attention due to their wide range of uses in the field of biomedicine. In specific, biopolymer-encapsulated Fe3O4 NPs were applied in cancer therapy owing to their biocompatibility and biodegradability. The current investigation describes a bio-inspired approach to synthesize chitosan-based Fe3O4 nanocomposite (NC) employing Cissus quadrangularis (CQ) plant extract in a sustainable manner. The physicochemical, morphological, compositional, surface texture and thermal stability properties of the biopolymer-coated nanocomposites were characterised using FT-IR, UV–vis, XRD, XPS, HR-SEM, TEM, TGA, BET and TGA analyses. The antibacterial efficacy was examined in strains of Escherichia coli and Staphylococcus aureus, which verified that the growth of bacterial pathogens was inhibited by a substantial increase in the concentration of composites. The DPPH assay results were utilized to assess the free radical scavenging activity. The in vitro anticancer activity was found to be significant against the human osteosarcoma (MG-63) cell line, with an IC50 value of 54 ± 0.50 μg/mL. The enhanced biocompatibility of NCs was confirmed by cytotoxic testing on human RBCs and normal L929 fibroblast cells.

Visible light-boosted photodegradation activity of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 supported heterojunctions for effective degradation of organic contaminates

Abstract One of the most important concerns in developing efficient heterojunction photocatalysts for the photodegradation of environmental contaminants is the enhancement and acceleration of photocarrier separation. In this study, novel nanocomposite photocatalysts of Ag–AgVO3 nanorods grafted with Zn0.5Mn0.5Fe2O4 metal ferrites nanoparticles were developed by using facial hydrothermal and coprecipitation techniques for the effective photodegradation of Rhodamine B (Rh B) under visible light exposure. The fabricated materials were analyzed in detail using scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDS), nitrogen adsorption/desorption, transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), vibrating sample magnetometer, and ultraviolet–visible diffuse reflectance spectroscopy (DRS). The results showed an efficient contribution when compared to the earlier research. The TEM showed a hybrid of nanorods of supported composite with metal ferrite and Ag attached on the surface, consistent with field emission scanning electron microscopy and EDS results. The DRS expressed a lower band gap for supported nanocomposites (1.5 eV), which, arranged with PL, showed a lower recombination rate of supported nanocomposites. The surface properties showed that the supported hybrid might be as small as 45.42 nm or as large as 20.33 nm compared with others. When comparing the photocatalytic activity of pure AgVO3, Ag/AgVO3, and Zn0.5Mn0.5Fe2O4 photocatalysts, the performance of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 nanocomposite photocatalyst was clearly superior (more than 99.9% degradation efficiency was achieved). The boosted activity the Ag–AgVO3/Zn0.5Mn0.5Fe2O4 photocatalyst system was justified by Z-system heterojunction induced by the plasmonic effect, and the suggested mechanism was investigated by quenching of reactive species by scavengers. The degradation performance was achieved under optimum conditions (pH = 2, 20 ppm of pollutant concentration, 120 mM of hydrogen peroxide, 1 g/L of catalysts dose). The results showed that after 240 min of visible irradiation resulted in the high (chemical oxygen demand) and (total organic carbon) reductions with a removal efficiency of (85) to (90%) for Rh B dye. The fabricated Ag–AgVO3/Zn0.5Mn0.5Fe2O4 nanocomposites were effective in the degradation of organic pollutants in wastewater treatment.

Synthesis and characterisation of novel beta-cyclodextrin based Fe3O4 nanocomposite: adsorption behaviour and photocatalytic dye degradation studies

ABSTRACT Novel Beta-Cyclodextrin-based Fe3O4 nanocomposite has been synthesised through copolymerisation by incorporating Fe3O4 nanoparticles into the polymer matrix. Ultraviolet-Visible (UV-Visible) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric (TGA) analysis, Point of Zero Charge, X-ray diffraction (XRD), and Scanning electron microscopy (SEM) analysis have been used to characterise the Fe3O4 Nanoparticles and β-CDHs@Fe3O4 nanocomposite. The synthesised β-CDHs@Fe3O4 nanocomposite has been utilised for the adsorption of methylene blue (MB) dye from aqueous solutions. The maximum percentage removal of MB dye at optimum pH 7 and was found to be 98.51%. The adsorption capacity (qe) of β-CDHs@Fe3O4 nanocomposite has been found to be 268.09 mg/g at optimum dosages 1.2 g/L, pH 7, temperature 25°C, concentration 100 mg/L and an agitation speed of 200 rpm. Adsorption data have been fitted with three isotherm models namely Langmuir, Freundlich, and Temkin, and it was found to be the best fit with the Langmuir isotherm model. Kinetic studies like the pseudo-first order, pseudo-second order, and intra-particle diffusion model were also performed to study the adsorption mechanism. Further, thermodynamic studies demonstrate that the reaction was exothermic and spontaneous. Photocatalytic degradation of MB dye under visible light has also been studied, and 79.01% degradation of the dye was observed. Also, desorption of the nanocomposite was performed, and it was found to be reusable up to 5 times with 90% dye-desorption in the fifth cycle.

Study of Fe3O4-NPs Coated with an Alcoholic Extract of C. Spinosa to Identify Appropriate IC50 HTC116 Cancer Cells

In this study, C. spinosa was used to prepare Fe3O4 nanoparticles using green synthesis, and an alcoholic extract of C. spinosa was used to coat them. The resulting Fe3O4 nanocomposite showed high IC50 activity against HTC116 cancer cells. We characterized the prepared Fe3O4-NP powder for phase size, shape, crystallographic arrangement, chemical composition, and surface charge using TEM, FESEM, XRD, FTIR, and zeta potential. Zeta potential confirmed NP surface charges -18.9 mV for Fe3O4 and -25 mV for Fe3O4 coated alcoholic extract, whereas XRD confirmed crystal shapes, and the FTIR study, functional groups at 505, 378, and 555 cm-1 showed Fe-O linkages in A1 (alcoholic extract), A2 (Fe3O4, green synthesis), and A3 (alcoholic extract coated with Fe3O4). C. spinosa exhibited C=C stretching at 1539 and 1558 cm-1, while functional groups A1, A2, and A3 observed C=O stretching at 1626, 1647, and 1743 cm-1. The green synthesis had spherical aggregates with an average size of 24.6±5.7 nm, and the alcoholic extract-coated synthesis had 27.3±7.5 nm. This was true even though the NPs had a crystal structure. Then, TEM measured 8.9±2.26 and 11.2±6.8 nm Fe3O4-NP thicknesses. The XRD analysis of the Fe3O4-NPs were 7.72 and 8.9 nm, respectively. The study found that Fe3O4 nanocomposites had the best IC50 at 32.49 μg/mL and the highest average viability at 20 μg/mL in code C. Following it were code B at 64.24 4.73% with an IC50 of 52.32 g/mL and code A at 69.25 1.07% with an IC50 of 78.95 g/mL. Code C had the lowest cell viability for HDF at 20 μg/mL, at 75.27±7.90%, with an IC50 of 569.47 μg/mL. Codes B and A came in second and third, with IC50s of 488.23 and 243.77 μg/mL, respectively, which was in line with what the literature said would happen. Following lengthy procedures, it may be a promising drug in the future.

Solvent‐Less Synthesis of Compositionally Tuned Mixed Metal (Ni−Zn) Ferrites for Enhanced Electrocatalytic Water Splitting and Supercapacitance

AbstractExploring efficient, abundant, economical and stable materials for sustainable energy applications, such as electrochemical water splitting and supercapacitance, is a challenging task. Mixed transition metal spinel ferrites can rationally be customized to attain these features and deliver enhanced electrochemical activity. The catalytic performance of spinels is remarkably influenced by tuning the cationic occupancy at the tetrahedral or octahedral position. Herein, a set of spinel Ni1‐xZnxFe2O4 (0≤x≤1) nanocomposites were obtained via a scalable solventless thermolysis of metal acetylacetonate precursors at relatively mild temperatures. A suite of techniques such as powder p‐XRD, EDX, SEM, TEM, HRTEM, and SAED were employed to confirm the formation of the Ni−Zn ferrite solid solutions. It was found that small amounts of Ni at tetrahedral sites were beneficial for charge storage and hydrogen evolution. For instance, Ni0.2Zn0.8Fe2O4 nanocomposite demonstrated superior HER activity with a much lower overpotential of 87 mV compared to the pristine NiFe2O4 (213 mV) or ZnFe2O4 (164 mV) catalysts. However, Ni‐occupied tetrahedral sites were not suitable for OER, whereby the pristine ZnFe2O4 displayed high catalytic activity with an overpotential of 330 mV, outperforming other electrode compositions. The study helps to identify suitable compositions and site tuning for HER, OER and supercapacitors.

Structural, electrical and magnetoresistance feature of PP+Fe3O4 + Multi-walled carbon nanotubes nano-hybrid based polymer nanocomposite

This work studied the role of the iron oxide and MWCNT in a change of the electrophysical properties of PP + Fe3O4 + MWCNT nanocomposite to evaluate the potential of these nanocomposites as magnetic field sensors and EMI materials. The morphology of the obtained nanocomposites was studied with a scanning electron microscope and investigated that the sizes of both magnetite nanoparticles and carbon nanotubes stay stable during the three-phase nanocomposite formation. In addition, the X-ray diffraction method revealed that MWCNT plays an essential role in the ordered structure-formation of a polymer nanocomposite more than iron oxide nanoparticles. Dielectric properties of the PP + Fe3O4 nanocomposite were studied. Both dielectric permeability and dielectric losses of PP+MWCNT+Fe3O4 nanocomposites were enhanced. The dielectric permeability of the nanocomposite increased due to the interphase polarization, which in turn related to the formation of ordered structure caused the partial arrangement of carbon nanotubes in the polymer. Furthermore, the study showed that the negative magnetoresistance effect of PP+MWCNT+Fe3O4 nanocomposites is more dependent on the amount of Fe3O4 nanoparticles than that of MWCNT, which explained by the spin polarization of Fe3O4 nanoparticles at room temperature. In this research, the PP+5%Fe3O4+1%MWCNT nanocomposites were considered to be an effective material for magnetic field sensors and EMI shielding.

Facile synthesis of magnetic intelligent sensors for the pH-sensitive controlled capture of Cr(vi).

In this work, intelligent pH-sensitive sensors (Fe3O4/RhB@PAM) for Cr(vi) detection were successfully synthesized based on polyacrylamide (PAM) and Rhodamine B (RhB) co-modified Fe3O4 nanocomposites. The characterization results indicated that the sensors had many favorable properties, including suitable size, stable crystal structure and excellent magnetic response performance (47.59 emu g-1). In addition, the fluorescence changes during the detection process indicated that Fe3O4/RhB@PAM were "ON-OFF" intelligent sensors. When the Fe3O4/RhB@PAM sensors were placed in acidic Cr(vi) solution (pH 4), PAM acted as a pH-responsive "gatekeeper" releasing RhB, and the fluorescence intensity of released RhB was weakened by the complexation of Cr(vi). Furthermore, the fluorescence changes of the magnetic sensors were remarkably specific for Cr(vi) even in the presence of other competitive cations, and the limit of detection (LOD) for Cr(vi) was lower (0.347 μM) than the value recommended by the World Health Organization (0.96 μM). All the results presented in this study showed that the Fe3O4/RhB@PAM sensors had significant potential for Cr(vi) detection in acidic environmental samples.