2O3 Nanocomposite Research Articles

Adsorption removal of nitrate by a novel magnetic zeolite adsorbent (zeolite/γ-Fe2O3 nanocomposite) in solution

Adsorption removal of nitrate by a novel magnetic zeolite adsorbent (zeolite/γ-Fe2O3 nanocomposite) in solution

Synthesis and characterization of hematite (α-Fe2O3) reinforced polylactic acid (PLA) nanocomposites for biomedical applications

This study presents preliminary findings on the performance of the stimuli-responsive PLA/α-Fe2O3 nanocomposites under the magnetic stimulus with varying concentrations of hematite (α-Fe2O3) nanoparticles. The effect of varying nanoparticle concentrations on the structural and thermal properties was examined using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Subsequently, the magnetic field with various intensities was generated using a vibrating sample magnetometer in a controlled environment. The resulting deformation rate of the nanocomposites was observed in response to changing magnetic fields. The results revealed that the PLA/α-Fe2O3 nanocomposites could be potential materials for biomedical applications, i.e., cardiovascular stents, which can provide the desired stimulus to treat post-stenting complications without the need for secondary surgical procedures. In future studies, the synthesized PLA/α-Fe2O3 nanocomposites will be adopted for 3D printing (3DP) processes to develop patient-specific cardiovascular stents and to evaluate their biomechanical performance.

Parametric Optimization of Ball-Milled Bimetallic Nanoadsorbents for the Effective Removal of Arsenic Species

Arsenic (As) removal from portable water bodies using the nanotechnology-based adsorption technique offers a unique method to lower the As contamination below the World Health Organization’s (WHO) maximum contaminant level (MCL). This work promotes a systematic methodological-based adsorption study by optimizing the different parameters that affect As removal using TiO2/γ-Fe2O3 nanocomposites (T/M NCs) prepared with the green, facile, and cost-effective ball milling method. The studies using X-ray Diffraction (XRD) illustrate the structural modifications with variations in the constituting T/M ratios, with high-resolution transmission electron microscopy (HRTEM) being used for the NC morphological studies. The optical characterization studies showed that bandgap tuning between 2–2.8 eV reduced the maghemite (γ-Fe2O3) content in the NCs and the elemental analysis confirmed the desired stoichiometry of the NCs. The magnetic measurements showed that the magnetic interaction among the particles tends towards exchange coupling behavior as the weight ratio of γ-Fe2O3 content decreases in the NCs. The adsorption studies using the most efficient NCs with an optimized condition (NC dose (8 g/L), contact time (15 min), As concentration (2 ppm), and pH (4)) resulted in a more than 99% removal of As species, suggesting the excellent behavior of the synthesized nanomaterial for water treatment and making it more economical than other competing adsorption techniques and materials.

Simultaneous adsorption of heavy metals on mesoporous reduced graphene oxide/γ-Fe2O3 nanocomposites

Simultaneous adsorption of heavy metals on mesoporous reduced graphene oxide/γ-Fe2O3 nanocomposites

Facile synthesis of exfoliated graphite-supported cobalt ferrite (Co1.2Fe1.8O4) nanocomposite for the electrochemical detection of diclofenac

Diclofenac (DCF) is used to reduce inflammation substance, which causes pain and inflammation, in the human body. However, the overconsumption of DCF may cause life-threatening problems in humans. Therefore, it is necessary to detect DCF levels in human urine samples because it is excreted in the urine after taking DCF. We developed a facile synthetic route for obtaining an exfoliated graphite (Gr)-supported cobalt ferrite (EGr-Co1.2Fe1.8O4) nanocomposite using an ultrasonication method that does not involve calcination. The prepared EGr-Co1.2Fe1.8O4 nanocomposite was examined by various physicochemical characterization methods. The nanocomposites were successfully agglomerated on the exfoliated Gr surface under the optimized experimental conditions. An EGr-Co1.2Fe1.8O4 nanocomposite was employed to fabricate electrochemical sensors for the sensitive electrochemical detection of DCF in human urine samples. The EGr-Co1.2Fe1.8O4 modified screen-printed carbon electrode sensor shows excellent electrochemical activity toward DCF with excellent sensitivity (1.059 µA µM−1 cm−2) within an acceptable linear concentration range (0.01–23.1 µM) and a very low limit of detection (1 nM).

Solid-State Construction of CuOx/Cu1.5Mn1.5O4 Nanocomposite with Abundant Surface CuOx Species and Oxygen Vacancies to Promote CO Oxidation Activity.

Carbon monoxide (CO) oxidation performance heavily depends on the surface-active species and the oxygen vacancies of nanocomposites. Herein, the CuOx/Cu1.5Mn1.5O4 were fabricated via solid-state strategy. It is manifested that the construction of CuOx/Cu1.5Mn1.5O4 nanocomposite can produce abundant surface CuOx species and a number of oxygen vacancies, resulting in substantially enhanced CO oxidation activity. The CO is completely converted to carbon dioxide (CO2) at 75 °C when CuOx/Cu1.5Mn1.5O4 nanocomposites were involved, which is higher than individual CuOx, MnOx, and Cu1.5Mn1.5O4. Density function theory (DFT) calculations suggest that CO and O2 are adsorbed on CuOx/Cu1.5Mn1.5O4 surface with relatively optimal adsorption energy, which is more beneficial for CO oxidation activity. This work presents an effective way to prepare heterogeneous metal oxides with promising application in catalysis.

Synthesis, structural characterization, and optical properties of a novel hybrid nanocomposite of poly(9,9′-dihexyfluorene) and europium oxide nanoparticles

This research aimed to synthesize the new PHF/n-Eu2O3 nanocomposite, characterize its crystalline structures and morphologies, and correlates them with their optical properties. From the XRD patterns of pure PHF, n-Eu2O3, and PHF/n-Eu2O3 samples, adjusted by the Le Bail method, the unit cells and average apparent size of crystallites (43.86, 61.55, 85.59, and 58.05 Å) were obtained. The SAXS measurements showed that the samples of pure PHF and PHF/n-Eu2O3 are polydisperse. The maximum distance of the pair distribution function of pure PHF indicated a particle size of 67.21 nm, and for PHF/n-Eu2O3 it revealed a large nanoparticle formed by two components with diameters of 96.42 and 119.05 nm. Scanning electron microscopy (SEM) and SAXS revealed globular morphologies of nanoparticles of pure PHF, n-Eu2O3, and PHF/n-Eu2O3. The UV-Vis absorption and photoluminescence spectra showed a clear correlation with the ordering of the polymer chains, crystallinity, presence of the β-phase, and morphology of mixed nanoparticles in the nanocomposite.

Hydrothermal synthesis of novel heterostructured Ag/TiO2 /CuFe2 O4 nanocomposite: Characterization, enhanced photocatalytic degradation of methylene blue dye, and efficient antibacterial studies.

In this work, we reported the successful synthesis of novel Ag/TiO2 /CuFe2 O4 ternary nanocomposite by hydrothermal technique by using TiO2 /CuFe2 O4 binary nanocomposite precursor that was also prepared by hydrothermal treatment by using TiO2 nanoparticles and CuFe2 O4 nanoparticles synthesized via sol-gel method. The synthesized nanomaterials were accessed for their morphological, structural, and optical properties. X-ray diffraction (XRD) study reveals the formation of pure Ag/TiO2 /CuFe2 O4 ternary nanocomposite in which the Ag, TiO2 , and CuFe2 O4 are in anatase, spinal, and cubic crystal phases, respectively. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analyses of Ag/TiO2 /CuFe2 O4 ternary nanocomposite indicated granule-shaped morphology with bright spots of silver. The existence of Ti, O, Cu, Fe, and Ag without any other elements in the energy-dispersive X-ray spectroscopy (EDS) spectra of the prepared ternary nanocomposite depict its purity and its polycrystalline nature was confirmed by its selected area electron diffraction (SAED) pattern. The ternary nanocomposite was utilized for the methylene blue dye degradation with an optimum dose of 1.00 g/100 ml under ultraviolet (UV) light; the enhanced photocatalytic activity of the composite is attributed mainly due to the appreciable magnitudinal difference of positive charge of the valence band and negative charge of the conduction band of TiO2 and CuFe2 O4 ; meanwhile, the interfacially placed Ag acts as a sink for the elections. Also, the ternary nanocomposite showed satisfactory antibacterial activities. PRACTITIONER POINTS: The prepared ternary nanocomposite showed effective results in dye degradation and satisfactory antibacterial property. The concentration of methylene dye has decreased considerably in every degradation process which was accessed through UV-vis studies. The highest degradation by using the ternary nanocomposite archived at pH = 6 Appreciable antibacterial activity was achieved against a few Gram-positive strains and Gram-negative strains of bacteria. This research activity can open a broad area of research towards textile dye degradation and antibacterial studies.

α-Fe2O3 Nanoparticles Aided-Dual Conversion for Self-Powered Bio-Based Photodetector.

Eco-friendly energy harvesting from the surrounding environment has been triggered extensive researching enthusiasm due to the threat of global energy crisis and environmental pollutions. By the conversion of mechanical energy that is omnipresent in our environment into electrical energy, triboelectric nanogenerator (TENG) can potentially power up small electronic devices, serves as a self-powered detectors and predominantly, it can minimize the energy crisis by credibly saving the traditional non-renewable energy. In this study, we present a novel bio-based TENG comprising PDMS/α-Fe2O3 nanocomposite film and a processed human hair-based film, that harvests the vibrating energy and solar energy simultaneously by the integration of triboelectric technology and photoelectric conversion techniques. Upon illumination, the output voltage and current signals rapidly increased by 1.4 times approximately, compared to the dark state. Experimental results reveal that the photo-induced enhancement appears due to the effective charge separation depending on the photosensitivity of the hematite nanoparticles (α-Fe2O3 nanoparticles) over the near ultraviolet (UV), visible and near infrared (IR) regions. Our work provides a new approach towards the self-powered photo-detection, while developing a propitious green energy resource for the circular bio-economy.

Nature inspired hierarchical structures in nano-cellular epoxy/graphene-Fe3O4 nanocomposites with ultra-efficient EMI and robust mechanical strength

• Nacre/bone like hierarchical structures in epoxy-based nanocomposites. • Simple compression molding with eco-friendly supercritical CO 2 foaming process to achieve porous layered nanocomposites. • Lightweight nano-cellular (52.6 nm) nanocomposite with 75 wt.% rGO-Fe 3 O 4 loading. • Low density (1.26 g/cm 3 ) and high specific EMI SE >5200 dB/cm 2 /g, with preserved tensile strength of 67 MPa achieved. Hierarchical layered structures, whether in a compact form like nacre or a porous manner like bone, are well known for their combined features of high stiffness, strength, and lightweight, inspiring many man-made materials and structures for high performance applications. The use of nacre/bone like hierarchical structures in polymer nanocomposites can achieve excellent mechanical and functional properties with high filler volume fractions after carefully aligning functional nanofillers, although the fabrication and processing remain a great challenge. In this work, a bio-inspired lightweight nano-cellular epoxy/graphene-Fe 3 O 4 nanocomposite with high nanofiller loading of 75 wt.% was successfully fabricated by combining features from both nacre and bone structures, via a simple compression molding process together with an eco-friendly supercritical CO 2 foaming process to achieve robust mechanical strength and excellent electromagnetic interference (EMI) shielding effectiveness (SE) simultaneously. Highly aligned graphene-Fe 3 O 4 nanoplatelets with well controlled nanoscale porous structures (52.6 nm) enabled both low density (1.26 g/cm 3 ) and high specific EMI SE >5200 dB/cm 2 /g, as well as preserved tensile strength of 67 MPa. This study provides a sustainable route to fabricate nature mimicked structures with high performance and high flexibility for a wide range of applications, from portable electronics to healthcare devices.

Influence of Cr2O3 nanoparticles on the structural, optical, thermal and electrical properties of PEO/CMC nanocomposites

In the present paper, different concentrations of chromium oxide (Cr2O3) nanoparticles (≤ 0.6 wt%) were incorporated within PEO/CMC polymer blend to produce nanocomposite films using the casting technique. X-ray diffraction was performed on PEO/CMC-Cr2O3 nanocomposites. The main X-ray peaks of Cr2O3 were observed and defined as cubic structure and orthorhombic shape. The average particle size was calculated by Scherer’s equation in the range between 50 and 60 nm. A decrease of some IR bands after the addition of Cr2O3 nanoparticles was found, which was attributed to the interactions between PEO/CMC and Cr2O3. The effect of Cr2O3 nanoparticles on optical properties such as absorbance and optical energy gap (Eg) was characterized using UV–Vis spectroscopy. The Eg was reduced after the addition of Cr2O3 nanoparticles. The AC conductivity (σac), dielectric constant (ε′), dielectric loss (\({\varepsilon }^{{^{\prime}}{^{\prime}}}\)) and the dielectric modulus (\({\text{M}}^{{^{\prime}}}\text{and }{\text{M}}^{{^{\prime}}{^{\prime}}}\)) were calculated at the frequency range of 0.1 Hz -7 GHz. The increase in direct conductivity (σdc) indicates the resulting free charge density or charge mobility. The calculated values of both ε′ and \({\varepsilon }^{{^{\prime}}{^{\prime}}}\) were decreased with increasing the frequency. The addition of Cr2O3 nanoparticles causes the formation of a charge-transfer complex. The Cole–Cole plot between (\({\text{M}}^{{^{\prime}}}\text{ and }{\text{M}}^{{^{\prime}}{^{\prime}}}\)) shows a semi-circular shape which discuses according to a non‐Debye method.

Green synthesis, characterization and anti-cancer capability of Co0.5Ni0.5Nd0.02Fe1.98O4 nanocomposites

In this study, Co0.5Ni0.5Nd0.02Fe1.98O4 nanoparticles CoNiNd (NPs) were synthesized by combustion method linked with biosynthesis with and without different plant extracts such as Lavender, Ginger, Flax-Seed, Lemon Juice, Tragacanth Gum, and Dates Fruit. Co0.5Ni0.5Nd0.02Fe1.98O4 nanoparticles (NPs) with plant extracts (CoNiNd plant extracts) were analyzed by XRD, TEM and SEM methods. The structure of Co-Ni spinel ferrite was confirmed by XRD and the shape and the size of nanoparticles were examined via SEM and TEM and the size was found between 17 and 25 nm. The anti-cancer activity of NPs on cancer cells such as human colorectal carcinoma (HCT-116) and human cervical cells (Hela) were investigated. The cytotoxicity of was examined by MTT assay and followed by measuring the inhibitory concentration (IC50) values after 48 h treatments. The cell viability assay confirmed a decrease in the cancer cell viability post NPs treatments and showed dose-dependent inhibitory action. The treatments of CoNiNd (NPs) and CoNiNd plant extracts via Lavender plant extract showed most profound inhibitory action on both cancer cells than extracts other plant extracts. The IC50 values were for HCT-116 cells were found to be in range of 15.75–42.55 µg/mL and 13.44 to 35.65 µg/mL for HeLa cells. In contrast, the treatment of CoNiNd (NPs) and CoNiNd plant extracts showed inhibitory action but the percentage of inhibition was higher in HEK-293 cells. Our results showed that CoNiNd (NPs) and CoNiNd plant extracts possess potential application in the colon and cervical cancer treatments and we recommend molecular analysis of NPs mediated cancer cell death for future applications.

Hematite nanoparticles decorated nitrogen-doped reduced graphene oxide/graphitic carbon nitride multifunctional heterostructure photocatalyst towards environmental applications

The NrGO/g-C3N4/α-Fe2O3nanocomposites were synthesized by a facile synthetic approach and applied towards photocatalytic Cr(vi) reduction, 2,4-DNP photodegradation, and photocatalytic H2evolution applications.

Tuning of Memory Effect with Magnetic Field of Ni and Co - Doped Ferrite- Pbzr0.58ti0.42o3 Nanocomposite

Tuning of Memory Effect with Magnetic Field of Ni and Co - Doped Ferrite- Pbzr0.58ti0.42o3 Nanocomposite

Sustainable green approach to synthesize Fe3O4/α-Fe2O3 nanocomposite using waste pulp of Syzygium cumini and its application in functional stability of microbial cellulases

Synthesis of nanomaterials following green routes have drawn much attention in recent years due to the low cost, easy and eco-friendly approaches involved therein. Therefore, the current study is focused towards the synthesis of Fe3O4/α-Fe2O3 nanocomposite using waste pulp of Jamun (Syzygium cumini) and iron nitrate as the precursor of iron in an eco-friendly way. The synthesized Fe3O4/α-Fe2O3 nanocomposite has been extensively characterized through numerous techniques to explore the physicochemical properties, including X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, Ultraviolet-Vis spectroscopy, field emission scanning electron microscope, high resolution transmission electron microscope and vibrating sample magnetometer. Further, efficiency of the Fe3O4/α-Fe2O3 nanocomposite has been evaluated to improve the incubation temperature, thermal/pH stability of the crude cellulase enzymes obtained from the lab isolate fungal strain Cladosporium cladosporioides NS2 via solid state fermentation. It is found that the presence of 0.5% Fe3O4/α-Fe2O3 nanocomposite showed optimum incubation temperature and thermal stability in the long temperature range of 50–60 °C for 15 h along with improved pH stability in the range of pH 3.5–6.0. The presented study may have potential application in bioconversion of waste biomass at high temperature and broad pH range.

NIR red luminescent doped Ag·(Y0.95Eu0.05)2O3 nanocomposite for 3-Chlorophenol sensor probe and anti-MDR bacterial application

Nanocomposite, Ag·(Y0.95Eu0.05)2O3 was characterized by XRD, SEM, EDS, TEM, FTIR and PL. Cubic morphology of Ag·(Y0.95Eu0.05)2O3 nanocomposite was observed with an average crystallite size of 43.78 nm. The materials showed excellent low temperature NIR red PL properties at 100 K, when excited by HeCd laser at 325 nm. The materials exhibited remarkable biological properties against MDR bacteria. The proposed sensor was assembled by depositing Ag·(Y0.95Eu0.05)2O3 nanocomposite on the flat part of a GCE to result a thin layer of nanocomposite and the sensor was applied to detect 3-CP in buffer solution in an electrochemical approach. To evaluate the sensor performances, the sensor calibration by plotting current versus concentration of 3-CP is executed, where currents data are distributed on a line from 0.1 nM to 0.01 mM defined as linear dynamic range (LDR) for 3-CP detection in buffer solution. The sensitivity of 3-CP sensor is calculated based on the slope of LDR considering the active surface area of GCE, which is equal to 23.5189 µAµM−1cm−2. The limit of detection (LOD) is calculated from the signal/noise ratio of 3, which is equal to 40.37 ± 2.02 pM. Besides this, the sensor parameters including reproducibility, response time and stability for long-time performance are evaluated in detail and found as reliable. Moreover, the real-time applicability of 3-CP sensor is tested by the electrochemical analysis of collected samples from environmental sources.

DC Surface Flashover of Epoxy Resin/γ-Al2O3 Nanocomposites for Current Lead Insulation

The current lead insulation of the high temperature superconducting DC current limiter is in the terrible working environment of strong electric field and temperature gradient field from room temperature to liquid nitrogen (LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) temperature. Bisphenol F epoxy resin, as a common terminal insulation material, is prone to surface flashover during equipment operation, which leads to premature failure of insulation. In order to improve the reliability of the terminal insulation system, epoxy resin/γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanocomposites were prepared. The dielectric constant, DC conductivity, trap distribution, partial discharge characteristics and DC surface flashover voltage of the nanocomposites at room temperature and in LN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> were measured and analyzed. The results show that with the increase of γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanoparticles content, the DC surface flashover voltage of the nanocomposites first increases and then decreases, and the partial discharge inception voltage generally increases. Appropriate γ-Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanoparticles doping can effectively inhibit the generation and development of surface discharge.

Preparation of n-ZnO/p-Co3O4 heterojunctions from zeolitic imidazolate frameworks (ZIF-8/ZIF-67) for sensing low ethanol concentrations

Nano-heterojunctions of n-ZnO/p-Co3O4 with varying molar ratios of Co3O4 derived from a zeolitic imidazolate framework (ZIF-8/ZIF-67) were efficiently synthesized and well-characterized. The heterojunction-based gas sensors were then used for sensing various gases, including ethanol. Owing in part to the ZIF-8/ZIF-67 structure, the calcined n-ZnO/p-Co3O4 with 30 mol% Co3O4 was the best sensor, in-terms of high response, outstanding selectivity, and good repeatability for low concentrations of ethanol at 300 °C. According to detailed analysis, the high ethanol-sensing performance of the n-ZnO/p-Co3O4 nanocomposite could be attributed to the high-porosity of sensing materials, formation of p-n heterojunction at interfaces, the catalytic ability of Co3O4, and the high crystallinity of the ZnO phase in the nano-heterojunctions.

Sustainable synthesis of Cu NPs decorated on pectin modified Fe3O4 nanocomposite: Catalytic synthesis of 1-substituted-1H-tetrazoles and in-vitro studies on its cytotoxicity and anti-colorectal adenocarcinoma effects on HT-29 cell lines

A great deal of modern catalytic research orients around the architecturally designed bio-engineered catalysts. In this context, we have adorned Cu NPs over pectin encapsulated Fe3O4 NPs. The Cu NPs were generated following a biogenic green pathway over the core-shell type nanocomposite promoted by Mentha Pulegium flower extract as natural reducing/stabilizing agent. The as-synthesized nanocomposite was meticulously characterized by using a wide range of physicochemical techniques like FT-IR, FESEM, TEM, EDX, elemental mapping, VSM, XRD and ICP-OES analysis. The catalyst was explored in the synthesis of diversely substituted 1H-tetrazoles via three component coupling reaction (MCR), under solvent-less conditions affording high to excellent yields. Heterogeneity of the catalyst was measured through its excellent reusability, hot-filtration test and leaching study. The nanocomposite was also explored biologically in the anticancer assays. In the cytotoxicity and anti-human colon carcinoma studies, the nanocomposite was treated to colorectal adenocarcinoma (HT-29) cell line following MTT assay. The cell viability of malignant colon cell line reduced dose-dependently in the presence of Cu/[email protected]3O4 nanocomposite. IC50 values of the nanocomposite were observed to be 1450.84 μg/mL against HT-29 cell line. The outstanding results showed by the developed nanocomposite, could be highly promising in cancer management in near future.

NiO/CeO2-Sm2O3 nanocomposites for partial oxidation of methane: In-situ experiments by dispersive X-ray absorption spectroscopy

In this work, we analyze Sm2O3-doped CeO2 (SDC) nanopowders and NiO/SDC nanocomposites in terms of sample reducibility and catalytic activity for partial oxidation of methane. We assess the role of the average crystallite size and specific surface area in Ni and Ce reduction kinetics by in-situ X-ray absorption spectroscopy experiments in diluted H2 and CH4/O2 mixtures. Our results indicate that crystallite size and surface area play a key role in CH4 activation through modification of the sample redox behavior. The oxidation of the metallic phase is the main cause of sample deactivation. A clear relationship is established between the temperature of maximum Ni oxidation rate and grain size. An interplay between Ce atoms from the support and Ni from the active phase was observed during the experiments, evidencing a complex relationship between oxygen vacancy concentration and catalytic activity. A high Ce3+ content in catalyst support was detrimental to catalytic activity