Fe3O4 Nanoparticles Research Articles

Bifunctional electrode materials: Enhancing microbial fuel cell efficiency with 3D hierarchical porous Fe3O4/Fe-N-C structures

The rational development of high-performance anode and cathode electrodes for microbial fuel cells (MFCs) is crucial for enhancing MFC performance. However, complex synthesis methods and single-performance electrode materials hinder their large-scale implementation. Here, three-dimensional hierarchical porous (3DHP) Fe3O4/Fe-N-C composites were prepared via the hard template method. Notably, Fe3O4/Fe-N-C-0.04-600 demonstrated uniformly dispersed Fe3O4 nanoparticles and abundant Fe-Nx and pyridinic nitrogen, showing excellent catalytic performance for oxygen reduction reaction (ORR) with a half-wave potential (E1/2) of 0.74 V (vs. RHE), surpassing Pt/C (0.66 V vs. RHE). Moreover, Fe3O4/Fe-N-C-0.04-600 demonstrated favorable biocompatibility as an anode material, enhancing anode biomass and extracellular electron transfer efficiency. Sequencing results confirmed its promotion of electrophilic microorganisms in the anode biofilm. MFCs employing Fe3O4/Fe-N-C-0.04-600 as both anode and cathode materials achieved a maximum power density of 831.8 ± 27.7 mW m−2, enduring operation for 38 days. This study presents a novel approach for rational MFC design, emphasizing bifunctional materials capable of serving as anode materials for microorganism growth and as cathode catalysts for ORR catalysis.

A novel stearic acid/expanded graphite/Fe3O4 composite phase change material with effective photo/electro/magneto-triggered thermal conversion and storage for thermotherapy applications

Composite phase change materials (CPCMs) have demonstrated high potential in thermotherapy; however, their poor energy conversion limits thermal−charge performance, thus negatively affecting their practical applications. Herein, we combined stearic acid (SA), expanded graphite (EG), and Fe3O4 nanoparticles (NPs) to obtain an 80 wt% SA/EG/Fe3O4 CPCM with multisource−triggered thermal conversion and storage abilities. The CPCM was equipped with a photothermal conversion facilitated by high light absorption of EG and localized surface plasmon resonance of Fe3O4. The high electrical conductivity of EG also offered the CPCM with an effective electrothermal conversion. An accelerated magnetothermal conversion was further achieved for the CPCM owing to the superparamagnetism of Fe3O4 NPs. Resultantly, the 80 wt% SA/EG/Fe3O4 CPCM could be facily charged as applied with either low−energy electricity (2.0 V), actual sunlight radiation (98−110 mW/cm2), or alternating magnetic field (120 W). In addition, it exhibited relatively high thermal storage capacity (152.4 J/g), excellent leakage resistance, and high thermal stability, conductivity, and cycling reliability. As in the form of a heat pack, the 80 wt% SA/EG/Fe3O4 CPCM maintained a heat release to a human back within 50–52 °C for 34 min, overtaking the criteria for high−temperature thermotherapy. The proposed multisource−triggered thermal conversion abilities and suitable thermal properties made SA/EG/Fe3O4 CPCM promising for multiple energy utilization and practical thermotherapy applications.

Green synthesis and characterization of trisubstituted imidazole derivatives by an ecofriendly and efficient heterogenous nanocatalyst based on magnetite nanoparticles coated modified nanocellulose

In the present work, a nanocellulose based magnetic nanocomposite [(pH-PDA-DANC)@Fe3O4NPs] was synthesized by an ecofriendly and a simple protocol and characterized by means of different techniques such as Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) equipped with an Energy Dispersive X-ray (EDX) probe and the Value Stream Mapping (VSM). The theoretical study of [(pH-PDA-DANC)@Fe3O4NPs] was investigated using Density Functional Theory (DFT) at the DFT-D3/ B3LYP/LanL2DZ level of theory to explore the nature of the interactions between the (pH-PDA-DANC) ligand and magnetite nanoparticles. The results indicate that the Fe3O4 nanoparticles form covalent bonds with the N-ring of the ligand. Then, it was used as a catalyst in the green and efficient procedure for one-pot multicomponent syntheses of imidazole derivatives by the condensation of benzil or 9.10-phenanthrenequinone, benzaldehyde derivatives and ammonium acetate. The catalytic reaction provided the synthesis of above imidazole derivatives with high reaction efficiency (80 %-98.1 %) in a short reaction time (3 h) and in presence of a minimum amount of ethanol. The identification and structure of imidazole derivatives was determined analyzing the 1H NMR (Nuclear Magnetic Resonance) and FTIR spectra. This procedure has several advantages compared to the conventional method such as the high yields, short reaction times, easy separation of the nanocatayst from the reaction mixture by using a magnet, and the reusability of the catalyst.

Enhanced functionalization of superparamagnetic Fe3O4 nanoparticles for advanced drug enrichment and separation applications

Backgroundsuperparamagnetic ferroferric oxide (Fe3O4) nanoparticles can be extensively functionalized for applications in drug enrichment and separation. Their high magnetic responsiveness and controllable surface modification enable rapid drug enrichment and separation under external magnetic fields. This study aimed to enhance the application potential of superparamagnetic Fe3O4 nanoparticles in the field of drug enrichment and separation by functionalizing these nanoparticles to improve their biocompatibility and targeting capabilities.Methodssuperparamagnetic Fe3O4 nanoparticles functionalized with dopamine were synthesized using benzyl alcohol as the solvent and iron acetylacetonate as the precursor. The dopamine-functionalized superparamagnetic iron oxide nanoparticles were used to analyze protein enrichment and separation. Characterization of the nanoparticles was conducted, including analysis of particle size distribution, Zeta potential, and fluorescence spectra using a fluorescence spectrophotometer.Resultsthe Fe3O4 nanoparticles maintained high magnetism from the original material and exhibited uniform particle size distribution and stable Zeta potential. The saturation magnetization of dopamine-functionalized superparamagnetic Fe3O4 nanoparticles showed no significant difference compared to before coating, indicating minimal influence of dopamine on the internal magnetic core of the nanoparticles. The Fe3O4 nanoparticles demonstrated good biocompatibility and stability.Conclusionfunctionalization of superparamagnetic Fe3O4 nanoparticles significantly enhances their efficiency in drug enrichment and separation processes, suggesting broad applications in the pharmaceutical industry.

Dual bioinspired superhydrophobicity and magnetically-induced self-healing ferrofluid-based SLIPS to inhibit corrosion of copper

Copper has extensive industrial applications. However, the susceptibility to corrosion makes it vulnerable in harsh environments. Bioinspired coating presents a novel approach to address copper corrosion. Bioinspired from lotus leaves and pitcher plants, this research endeavors to create superhydrophobic and ferrofluid-infused surfaces (FIS) on copper substrate. Firstly, a one-step electrodeposition method is employed to fabricate superhydrophobic surface on copper. Secondly, Fe3O4 nanoparticles are sequentially modified with dopamine hydrochloride and dodecanethiol to endow surface hydrophobicity. Then, the modified Fe3O4 is dispersed in oil to create a magnetic fluid, which is finally infused onto the superhydrophobic matrix, forming the FIS coating. Electrochemical testing confirms the high protective effect of the bio-inspired superhydrophobic and magnetic fluid composite coating against corrosion. The FIS coating exhibits a prominent low-frequency impedance modulus (7.73 × 106 Ω·cm²) even after immersion in NaCl solution for 60 d. Furthermore, the coating demonstrates an outstanding magnetic-driven self-healing capability, as evidenced by the minimal decrease in the |Z|0.01 Hz value (remaining as high as 109 Ω·cm²) even after undergoing six cycles of scratching and self-healing process. This corrosion resistance can be attributed to the combined effects of the accommodating effect of superhydrophobic matrix and the self-healing property of the magnetic fluid under the magnetic field. This dually bio-inspired coating technology offers significant advantages for copper applications in harsh environments.

Fabrication of ZMF@PS composite microspheres as T2 contrast agents with enhanced contrast performance and magnetic properties

The impacts of nanoplastics on the environment and organisms are gradually increasing, using MRI to detect the metabolic pathways of nanoplastics has low sensitivity and requires magnetic particles for enhanced visualization. In this study, we used Mn0.6Zn0.4Fe2O4 nanoparticles as magnetic particles and coated them with polystyrene to afford polystyrene composite microspheres (ZMF@PS) with enhanced contrast performance. The effects of the polymerization parameters on the morphology and loading rate of the magnetic ZMF@PS composite microspheres were investigated. In addition, the effect of the magnetic contrast agent (ZMF particles) on the magnetic properties of the ZMF@PS composite microspheres was examined. The results show that when MAA and KPS quantities are 1 mL and 0.02 g, respectively, ZMF was uniformly distributed in the ZMF@PS composite microspheres exhibiting a good coating effect, with an average microsphere size of only 151.09 nm. Regarding the contrast performance, an increase in the ZMF content increased the loading rate, saturation magnetization intensity, and relaxation rate of the ZMF@PS composite microspheres.

Characterization and applications of iron oxide nanoparticles synthesized from Phyllanthus emblica fruit extract

Nanotechnology is a treasure trove of diversified themes which are endowed with broad applications. Herein, iron oxide (Fe2O3) nanoparticles were synthesized using Phyllanthus emblica aqueous fruit extract. The UV-Visible spectrum exhibited a surface plasmon resonance peak at 295nm. Fourier Transform Infrared Spectroscopy provided insight into the functional groups responsible for capping. X-ray diffraction analysis authenticated the crystalline nature of nanoparticles, while energy dispersive X-ray spectroscopy divulged that iron and oxygen comprised 54% of the nanoparticles’ weight. Scanning electron microscopy established irregular morphology and agglomeration of nanoparticles. The Fe2O3 nanoparticles validated potent antimicrobial activity against 11 bacterial and 1 fungal isolates. The biggest zone of inhibition (23mm) was measured against S. enterica, whereas the smallest zone of inhibition (12mm) was documented against C. albicans and E. coli. The values for minimum inhibitory concentration ranged between 10 and 15μg/ml for all microbes. Nevertheless, no synergy was exhibited by the nanoparticles with any of the selected antibiotics (Fractional Inhibitory Concentration Index > 1). The photocatalytic dye degradation capability of Fe2O3 nanoparticles was assessed and the observations implied a significant increase in degradation of methyl red although, not of methylene blue. Furthermore, the nanoparticles were in possession of substantial antioxidant (34–38%) and anti-inflammatory (31–38%) capacities. Consequent upon the robust activities of P. emblica-mediated nanoparticles, these can be scrutinized for biomedical and environmental implementations in future.

Magnetic Nanoparticles with On-Site Azide and Alkyne Functionalized Polymer Coating in a Single Step through a Solvothermal Process.

Background/Objectives: Magnetic Fe3O4 nanoparticles (MNPs) are becoming more important every day. We prepared MNPs in a simple one-step reaction by following the solvothermal method, assisted by azide and alkyne functionalized polyethylene glycol (PEG400) polymers, as well as by PEG6000 and the polyol β-cyclodextrin (βCD), which played a crucial role as electrostatic stabilizers, providing polymeric/polyol coatings around the magnetic cores. Methods: The composition, morphology, and magnetic properties of the nanospheres were analyzed using Transmission Electron and Atomic Force Microscopies (TEM, AFM), Nuclear Magnetic Resonance (NMR), X-ray Diffraction Diffractometry (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), Matrix-Assisted Laser Desorption/Ionization (MALDI) and Vibrating Sample Magnetometry (VSM). Results: The obtained nanoparticles (@Fe3O4-PEGs and @Fe3O4-βCD) showed diameters between 90 and 250 nm, depending on the polymer used and the Fe3O4·6H2O precursor concentration, typically, 0.13 M at 200 °C and 24 h of reaction. MNPs exhibited superparamagnetism with high saturation mass magnetization at room temperature, reaching values of 59.9 emu/g (@Fe3O4-PEG6000), and no ferromagnetism. Likewise, they showed temperature elevation after applying an alternating magnetic field (AMF), obtaining Specific Absorption Rate (SAR) values of up to 51.87 ± 2.23 W/g for @Fe3O4-PEG6000. Additionally, the formed systems are susceptible to click chemistry, as was demonstrated in the case of the cannabidiol-propargyl derivative (CBD-Pro), which was synthesized and covalently attached to the azide functionalized surface of @Fe3O4-PEG400-N3. Prepared MNPs are highly dispersible in water, PBS, and citrate buffer, remaining in suspension for over 2 weeks, and non-toxic in the T84 human colon cancer cell line, Conclusions: indicating that they are ideal candidates for biomedical applications.

Nanocomposites of Poly(n-Butyl Acrylate) with Fe3O4: Crosslinking with Hindered Urea Bonds, Reprocessing and Related Functional Properties.

In this contribution, we reported the synthesis of the nanocomposites of poly(n-butyl acrylate) with Fe3O4 nanoparticles (NPs) via dynamic crosslinking of poly(n-butyl acrylate)-grafted Fe3O4 NPs with hindered urea bonds (HUBs). Towards this end, the surfaces of Fe3O4 NPs were grafted with poly(n-butyl acrylate-ran-2-(3-tert-butyl-3-ethylureido)ethyl acrylate) chains [denoted as Fe3O4-g-P(BA-r-TBEA)] via living radical polymerization. Thereafter, 1,2-bis(tert-butyl)ethylenediamine was used as a crosslinker to afford the organic-inorganic networks with variable contents of Fe3O4 NPs and crosslinking densities. It was found that the fine dispersion of Fe3O4 NPs in the matrix of poly(n-butyl acrylate) was achieved. The nanocomposites exhibited excellent reprocessing properties, attributed to the introduction of HUBs. Owing to the crosslinking, the nanocomposites displayed excellent shape memory properties. Further, the nanocomposites possessed photo- and magnetic-thermal properties, which were inherited from Fe3O4 NPs. These functional properties allow triggering the shape shifting of the nanocomposites in an uncontacted fashion.

Enhanced nanofluid stability of Zn-doped iron oxide: Applications of ascorbic acid nanofluid in enhanced oil recovery

Ascorbic acid-coated, transition metal-doped Fe3O4 nanoparticles were successfully synthesized via coprecipitation. The synthesized Zn-doped Fe3O4 nanoparticles have an average diameter of approximately 30 nm. These nanoparticles exhibit ferromagnetic properties at room temperature, with the highest saturation magnetization approaching 40 emu/g and decreasing coercivity. The surface was functionalized with ascorbic acid, which served as a surfactant to ensure high dispersibility and stability of the Fe3O4 nanoparticles in a brine solution containing 30,000 ppm NaCl. Zeta potential and interfacial tension (IFT) measurements were conducted to assess the suspension quality, confirming the effectiveness of the ascorbic acid coating in stabilizing the nanoparticles.

Dual cross-linked magnetic gelatin/carboxymethyl cellulose cryogels for enhanced Congo red adsorption: Experimental studies and machine learning modelling

To achieve highly efficient and environmentally degradable adsorbents for Congo red (CR) removal, we synthesized a dual-network nanocomposite cryogel composed of gelatin/carboxymethyl cellulose, loaded with Fe3O4 nanoparticles. Gelatin and sodium carboxymethylcellulose were cross-linked using transglutaminase and calcium chloride, respectively. The cross-linking process enhanced the thermal stability of the composite cryogels. The CR adsorption process exhibited a better fit to the pseudo-second-order model and Langmuir model, with maximum adsorption capacity of 698.19 mg/g at pH of 7, temperature of 318 K, and initial CR concentration of 500 mg/L. Thermodynamic results indicated that the CR adsorption process was both spontaneous and endothermic. The performance of machine learning model showed that the Extreme Gradient Boosting model had the highest test determination coefficient (R2 = 0.9862) and the lowest root mean square error (RMSE = 10.3901 mg/g) among the 6 models. Feature importance analysis using SHapley Additive exPlanations (SHAP) revealed that the initial concentration had the greatest influence on the model’s prediction of adsorption capacity. Density functional theory calculations indicated that there were active sites on the CR molecule that can undergo electrostatic interactions with the adsorbent. Thus, the synthesized cryogels demonstrate promising potential as adsorbents for dye removal from wastewater.

New application of a dye-decolorizing peroxidase immobilized on magnetic nanoparticles for efficient simultaneous degradation of two mycotoxins

Nowadays the enzymatic approaches are the most promising strategies for mycotoxins detoxification in food stuffs. Herein, the dye-decolorizing peroxidase RhDypB from Rhodococcus jostii was studied for its ability to degrade two mycotoxins in both free and the immobilized enzyme forms. This enzyme was recombinantly expressed and purified, while Fe3O4 nanoparticles were prepared and modified with chitosan as the immobilization carrier. The immobilized enzyme Fe3O4@CS@RhDypB demonstrated degradation rate of 85.61 % toward aflatoxin B1, while it was firstly found to be able to degrade zearalenone with the rate of 86.52 %, at pH 4.0 on 30 °C. The degradation products were identified as aflatoxin Q1 and 15-OH-ZEN respectively. After 5 cycles of reuse, Fe3O4@CS@RhDypB still exhibited degradation rates of 38.50 % and 49.76 % toward the mycotoxins, indicating its high reusability. Moreover, Fe3O4@CS@RhDypB exhibited excellent stability after 10 days of storage. This work identified potential applications of nanoparticle-immobilized enzyme for biodegradation of mycotoxins in food industry.

Enhanced sonophoto-catalytic and adsorption capabilities of Fe3O4@MC/MWCNT-CuO/Ag for petrochemical organic pollutants degradation from industrial process streams

To address the problem of petrochemical organic pollutants in water, specifically monoethylene glycol (MEG) present in industrial process streams, in this research, we synthesized and evaluated a multifunctional nanocomposite, Fe3O4@MC/MWCNT-CuO/Ag. The nanocomposite was produced by combining magnetic Fe3O4 nanoparticles, methylcellulose (MC), multi-walled carbon nanotubes (MWCNTs), and CuO/Ag nanoparticles by an integrated synthesis process. A consistent dispersion of nanoparticles, with diameters ranging from 30-40 nm, was discovered by FESEM analysis, showing effective integration without aggregation. Effective synthesis was demonstrated by well-doped and evenly dispersed CuO and Ag nanoparticles. Functional groups that improve electrostatic interactions with contaminants hence enhancing catalytic performance and adsorption efficiency, were validated by FTIR analysis. XRD indicated an unchanged crystal structure with an average crystallite size of 8.67 nm. The anticipated elemental composition was verified by EDS & mapping. A VSM study revealed magnetic characteristics (9.33 emu/g) that simplify nanocomposite separation and reuse. TGA proved thermal stability to be up to 600 °C. A BET study showed a highly specific surface area of 67.661 m2/g, enhancing adsorption. According to DRS and PL studies, the bandgap was lowered by 1.31 eV, which led to better optical absorption. The nanocomposite exhibited notable MEG removal efficiency, with 72 % in adsorption, 65 % in photocatalysis, and 56 % in sonocatalysis. This makes it a promising alternative for the remediation of organic pollutants in water treatment.

Stearic acid modified Fe3O4/Y2O3 composite membranes for efficient oil-water separation

Traditional oil-water separation methods have low separation efficiency and are prone to environmental pollution. The development of low-cost and environmentally friendly novel oil-water separation membranes is of wide interest nowadays. In this work, stearic acid modified Fe3O4/Y2O3 (Fe3O4/Y2O3/SA) composite membranes are prepared on PET and cotton fabric using spraying and impregnation methods. Both Y2O3 and Fe3O4 nanoparticles are compounded on the surface of the substrate and modified using stearic acid impregnation. The results show that Fe3O4/Y2O3/SA composite membrane has a water contact angle of 152.5° and exhibits super hydrophobicity/lipophilicity. At the same time, the composite membrane has excellent oil-water separation performance, including high separation efficiency (99.92 %) for a variety of oil-water mixtures, and good stability in 15 cycles of separation tests. The mechanism of oil-water separation is discussed.

Synthesis of chitosan/Fe2O3/CuO-nanocomposite and their role as inhibitor for some biological disorders in vitro with molecular docking interactions studies

The hybrid material between the functional elements particularly with the polymer compounds as a nanocomposites are attractive in numerous fields. In the current work, chitosan/Fe2O3/CuO-nanocomposite has been successfully synthesized in situ via a coprecipitation method and characterized by several apparatuses. The X-ray diffraction cleared that chitosan/Fe2O3/CuO-nanocomposite was crystalline. Transmission Electron Microscopy (TEM) showed that the size of chitosan/Fe2O3/CuO-nanocomposite was of 17–85 nm. Candida albicans, Candida tropicalis, and Geotrichum candidum were inhibited employing the chitosan/Fe2O3/CuO-nanocomposite with inhibition areas of 25 ± 0.1 and 30 ± 0.1, and 23 ± 0.2 mm, respectively. Minimum inhibitory concentration (MIC) of chitosan/Fe2O3/CuO-nanocomposite was 15.62, 31.25, and 62.5 μg/mL for C. tropicalis, C. albicans, and G. candidum, respectively. Biofilm formation of C. albicans, C. tropicalis and G. candidum was inhibited at level of 95.31, 96.65, and 93.63 %, respectively at 75 % MIC of chitosan/Fe2O3/CuO-nanocomposite. The exposed C. tropicalis to chitosan/Fe2O3/CuO-nanocomposite showed severe damag of cytoplasm membrane with cell wall rupture. Chitosan/Fe2O3/CuO-nanocomposite reflected anticancer potential against human skin cancer (A-431) cells with IC50 of 77.79 ± 1.37 μg/mL. Moreover, wound heals was induced by chitosan/Fe2O3/CuO-nanocomposite with closure level 92.76 %. Molecular docking studies suggested strong binding of C. tropicalis (PDB ID: 8BH8) and A-431 (PDB ID: 5JJX) proteins with CuO nanoparticles and FeO nanoparticles.

Research on synthesis of imidazopyridine-sulfide-aryl derivatives: copper complex immobilized on Fe3O4 nanoparticles catalyzed one-pot C–H bond sulfenylation of imidazopyridines

This research report the development of an eco-friendly, magnetic nanocatalyst, Fe3O4@SiO2-ABHA-CuCl, for the efficient synthesis of diaryl sulfides incorporating imidazo[1,2-a]pyridine scaffolds. The catalyst was successfully prepared by immobilizing CuCl on magnetic Fe3O4 nanoparticles modified with 4-amino-3-hydroxybenzoic acid. Characterization revealed spherical nanoparticles with a size range of 15-30 nm. The catalyst exhibited excellent catalytic activity in promoting C–H bond sulfenylation of imidazopyridines using the green solvent PEG-400. Remarkably, the catalyst demonstrated exceptional recyclability over eight consecutive cycles without significant loss of activity. Comprehensive analysis confirmed the preservation of the catalyst's magnetic properties and structural integrity after repeated use.

Novel sensitive electrochemical detection of paracetamol using magnetite/MXene electrode by differential pulse voltammetry

In this research work, a novel electrochemical sensor-based Fe3O4/Ti3C2 MXene @ glassy carbon electrode (GCE) for the detection of paracetamol was prepared by simple ultrasonic method by combining Ti3C2 MXene and Fe3O4 nanoparticles. The Fe3O4/Ti3C2 MXene nanomaterial was characterized by the means of different techniques: X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM), nitrogen adsorption/desorption isotherms, as well as Fourier transform infrared spectroscopy (FTIR). The characterization results revealed the homogenous distribution of the prepared cubic Fe3O4 NPs within the prepared two-dimensional layered Ti3C2 MXene. The Fe3O4/Ti3C2 MXene @ GCE was used for the sensitive determination of the well-known analgesic drug paracetamol by differential pulse voltammetry (DPV). The prepared Fe3O4/Ti3C2 MXene @ GCE was characterized electrochemically, and the results showed that Fe3O4/Ti3C2 MXene @ GCE is a potential working electrode for the sensitive detection of paracetamol with very low detection limit (0.63 nM), within a linear dynamic range of 0.0–110.0 µM, high reproducibility and repeatability; with a very low relative standard deviation (SD%) for 7 days measurement (3.07–3.42 %), accuracy with a SD% of 0.89, high precision of 99.48 % in distilled water and 98.51 % in sea water. The proposed electroanalytical method was applied for the detection and quantification of paracetamol in real water samples, as well as different analgesic medical formulations, and the results showed outstanding accuracy and precision indicating the suitability of the Fe3O4/Ti3C2 MXene @ GCE electrode for the sensitive, accurate determination of paracetamol in diferrent matrices.

Recycling metal-organic framework residues (MOFRs) as bifunctional additives in fabricating porous ceramic membranes

In this work, Fe-MOF residues (Fe-MOFRs) were recycled and reused as a kind of bifunctional additives in the preparation of alumina ceramic membranes. To prevent the unwanted aggregation and grain growth of Fe-MOFR derived Fe2O3 nanoparticles at elevated temperature, Fe-MOFRs were premeditatedly introduced into the alumina powder matrix to construct the composite membrane layer. Results showed that the introduction of MOFRs could reduce the thickness of the membrane layer, attributing to the sacrificial organic linkers and high activity of Fe-MOFR-derived Fe2O3 nanoparticles. However, the thickness of the formed composite membrane layer abnormally increased once MOFRs were overloaded due to the aggregation. Impressively, the surface roughness and Young modulus of the membrane layer were characterized using atomic force microscopy (AFM). The Young modulus of pure alumina membranes showed the same trend as the height, while the trend gradually reversed once Fe-MOFRs were introduced, suggesting that the binding strength between the Fe-MOFR derived Fe2O3 nanoparticles were greatly enhanced. The composite membranes showed improved pure water flux and reduced filtration resistance.

Photoresponse properties of green-assisted Fe3O4 nanoparticles supported activated carbon

The photoresponse properties of green synthesized Fe3O4 (gFe3O4) supported-activated carbon (AC/g-Fe3O4) were studied using a photocurrent characterization approach. Preliminary UV–Vis analysis suggested a reduction in the band gap energy when activated carbon is incorporated into gFe3O4 nanoparticles (2.61 → 1.57 eV). The current-voltage characteristics indicate semiconductor features for both gFe3O4 and AC/gFe3O4 nanoparticles. The photodetector measurements indicate a significantly enhanced response for AC/gFe3O4 and can be attributed to increased rectification and photogenerated carriers emanating from the activated carbon incorporation. The study proposes AC/gFe3O4 nanocomposite as a novel material that can be used for the fabrication of photodetectors and other related optoelectronic devices.

Carbonization and Gasification of Cow‐Dung and Fe3O4 Nanoparticles at Different Operating Conditions for Hydrogen Production

AbstractCow dung is an abundant agricultural by‐product that poses disposal challenges. Converting this waste into a valuable energy resource aligns with sustainable waste management practices and contributes to a circular economy. This research aims at Cow dung disposal by carbonization and gasification for hydrogen generation and maximizes it by optimizing the process parameters. In the pyrolysis‐carbonization process, the influence of temperature on cow dung and its biochar characteristics was initially investigated. On the cow dung feedstock, different operating temperatures at about 400, 500, and 600 °C and response times of about 30, 60, and 120 min were tested. With CD450 as the feedstock, the gas concentrations and hydrogen yield were around 62 vol% and 0.69 m3 kg−1, respectively, for longer reaction times. Similar to this, the gas concentration and yield value for hydrogen at 600 °C gasification temperature is around 64 vol% and 0.91 m3 kg−1. Cow dung is evidently acceptable for larger hydrogen production at higher gasification temperatures and reaction times when the carbonization temperature is 450 °C. In addition, when compared to feedstock without adding nanoparticles, including Fe3O4 nanoparticles may increase the hydrogen concentration and yield by around 13.5 % and 4.21 %, respectively.