Magnetic Nickel Nanoparticles Research Articles

Gadolinium Schiff-base complex on nanocomposite of graphene oxide magnetic nanoparticles as a robust, reusable and chemoselective nanocatalyst in the C–C coupling reactions

Graphene is an important phase of carbon, which is easily available and oxidable to graphene oxide with a variety of applications. Therefore in this work, graphene oxide (GO) was synthesized, and further it was magnetized by nickel magnetic nanoparticles. The surface of graphene oxide magnetic nanoparticles (Ni-GO MNPs) was modified with (3-aminopropyl)triethoxysilane (APTES). On the other hand, (3,4-bis(−(2-hydroxybenzylidene)amino)phenyl)(phenyl)methanone Schiff-base ligand (bis(HBAPM)) was synthesized using condensation of salicylaldehyde and 3,4-diaminobenzophenone. In the next step, bis(HBAPM) was immobilized on the surface of modified Ni-GO MNPs toward synthesis of immobilized Schiff-base on Ni-GO MNPs (bis(HBAPM)@Ni-GO MNPs) as a heterogeneous Schiff-base ligand. In the final step, the gadolinium catalyst was stabilized on its surface (Gd-bis(HBAPM)@Ni-GO MNPs) as a robust, reusable, efficient, chemoselective, and novel nanocatalyst. Gd-bis(HBAPM)@Ni-GO MNPs were characterized by nitrogen adsorption/desorption, FT-IR, SEM imaging, EDS analysis, WDX analysis, XRD, and VSM analysis. After the characterization of Gd-bis(HBAPM)@Ni-GO MNPs, its catalytic performance was employed as a highly practical, retrievable, stable, and hybrid organic–inorganic catalyst in the carbon–carbon coupling of the Suzuki reaction. Due to the recoverability and heterogeneous nature of Gd-bis(HBAPM)@Ni-GO MNPs, it can recycled again for 5 runs.

Magnetic Nickel Nanoparticles Supported on Oxidized Charcoal as a Recoverable Catalyst for N-Alkylation of Amines with Alcohols

Magnetic Nickel Nanoparticles Supported on Oxidized Charcoal as a Recoverable Catalyst for <i>N</i>-Alkylation of Amines with Alcohols

Photothermal conversion of CO2 with high activity and stability over Ni-based composite nanochains

Solar-driven CO2 conversion to valuable products is a promising way to realize a carbon-neutral economy. Great progress has been made on photothermal catalysts with high selectivity and activity, but improved materials via a more efficient and cost-effective synthetic strategy are needed. Herein, we present a one-pot synthetic strategy of nickel/metal oxide nanostructured chains for the photothermal conversion of CO2 into methane. Nickel ions were in-situ reduced in a growth solution in the presence of alumina nanocrystals, where the formation and assembly of magnetic nickel nanoparticles decorated with Al2O3 nanocrystals simultaneously proceeded. The obtained composite nanochains exhibited a stable production rate of CH4 as high as 128 mmol·gcat−1·h−1 with ∼ 99% selectivity in continuous cycling test. The structure analysis of the Ni/Al2O3 composite indicates that a small amount of Al2O3 nanocrystals introduced in the nanocomposites not only ensures sufficient active site exposure to reactive molecules but also prevents the nickel nanoparticles from drastically sintering at high temperatures. The flexibility of this rapid synthesis strategy is also verified by using titania for the synthesis of Ni/TiO2 nanocatalysts, and stable catalytic performance has been achieved, suggesting its potential for practical solar-driven CO2 hydrogenation to valuable fuels.

Synergistic terahertz shielding effects of electrically conductive MXene and shape-controlled magnetic nickel in polyvinylidene fluoride (PVDF) composites

Terahertz (THz) shielding materials have garnered significant attention due to various potential applications in wireless communication, sensing, and defense. In this study, we present efficient THz shielding performance of polyvinylidene fluoride (PVDF) polymer composites incorporated with a mixture of MXene and shape-controlled nickel (Ni) nanoparticles. The PVDF/MXene/Ni composites demonstrated exceptional absorption coefficient and shielding effectiveness against unwanted THz electromagnetic waves, owing to the remarkable synergistic effect between electrically conductive Ti3C2Tx MXene and magnetic nickel nanoparticles. Notably, magnetic properties of Ni nanoparticles were controlled by external magnetic field applied during the synthesis process. Flower-like Ni nanoparticles synthesized under an external magnetic field exhibited enhanced magnetic properties compared to spherical Ni nanoparticles synthesized without an external field. As a result, a 20-µm thick PVDF/MXene/Ni composite film, with a 10 wt.% loading of flower-like Ni nanoparticles, demonstrated the THz shielding effectiveness of 34 dB at 1 THz. This shielding performance surpasses those of composite containing spherical Ni nanoparticles (26.7 dB) as well as previously reported shielding materials. These findings highlight an effective approach to tailor the THz shielding properties of polymer composites by modifying the composition and morphology of conductive and magnetic fillers.

A new neodymium complex on renewable magnetic biochar nanoparticles as an environmentally friendly, recyclable and efficient nanocatalyst in the homoselective synthesis of tetrazoles.

Inexpensive, stable, selective, and recyclable nanocatalysts, waste regeneration, and utilization of safe and available solvents are of interest and important factors in laboratory science and industrial applications of green chemistry. Therefore, herein, biochar nanoparticles (BNPs) were synthesized through chicken manure pyrolysis as a novel method for waste recycling. Then, in order to improve their recyclability, the obtained BNPs were magnetized using magnetic nickel nanoparticles. Then, the surface of the biochar magnetic nanoparticles (BMNPs) was modified by (3-chloropropyl)trimethoxysilane (3-CPTMS) and further a novel neodymium Schiff-base complex was immobilized on the surface of the modified BMNPs, denoted as Nd-Schiff-base@BMNPs. The obtained supported neodymium complex was used as a practical, selective, biocompatible, commercial, and reusable heterogeneous nanocatalyst. The biochar support of this nanocatalyst was formed from pyrolysis of chicken manure; therefore, it is cheap, economically viable, green and also compatible with the principles of green chemistry. Nd-Schiff-base@BMNPs acts selectively in organic reactions and also it can easily be recovered using an external magnet and reused, which is compatible with the principles of green chemistry. This nanocatalyst was characterized by wavelength-dispersive X-ray spectroscopy (WDX), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma (ICP), and N2 adsorption-desorption (BET method) techniques. In the next step, the catalytic utilization of Nd-Schiff-base@BMNPs was investigated in the homoselective synthesis of 5-substituted 1H-tetrazole compounds from [3 + 2] cycloaddition of sodium azide (NaN3) and organo-nitriles in PEG-400 as a green solvent. Utilizing PEG-400 as a solvent offers various advantages, e.g. cheap, readily available, and environmentally friendly solvent as well as rapid separation and high purity of products. Therefore, this work is fully compatible with the principles of green chemistry.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbon by graphitic carbonitride-nickel (g–C3N4–Ni) nanocomposite

The objective of the present study is to synthesize g-C3N4–Ni nanocomposites composed of graphitic carbon nitride and magnetic nickel nanoparticles for benzopyrene degradation, which is one of the most potent polycyclic aromatic hydrocarbons (PAH) molecules. The concocted g-C3N4–Ni nanocomposites contained confined nanospheres with a mean particle dimension of 22 nm. Batch adsorption studies revealed that a rise in adsorbent dosage elevates benzopyrene degradation percentage in both water and soil samples with respect to time. The increase in the benzopyrene concentration did not have much influence on the degradation efficiency, and hence, the minimal concentration of PAH molecule is essential for the effective adsorption by g-C3N4–Ni nanocomposites. The rise in pH tends to increase the degradation of Benzopyrene till 3 h of the incubation period, and beyond 3 h, the degradation percentage declines. With regard to the effect of light source, UV light has been shown to accelerate the degradation of benzopyrene by g-C3N4–Ni nanocomposites than sunlight. The adsorption kinetic and isotherm investigations have proven that the Pseudo-second order kinetic model and Freundlich isotherm model were appropriate for our study. Thus, the g-C3N4–Ni nanocomposites were found to be efficient as a photocatalyst for the adsorption of benzopyrene from environmental samples.

Functionalization of chitosan by metformin, nickel metal ions and magnetic nanoparticles as a nanobiocomposite for purification of alkaline phosphatase from hen's egg yolk

In this study, a novel and green chitosan-metformin/NiCl2/Fe3O4 nanobiocomposite was synthesized and used to purify alkaline phosphatase (ALPs) from hen's egg yolk. For this purpose, after functionalization of the chitosan biopolymer by terephthaloyl chloride-metformin ligand, the coordination with Ni(II) and magnetization process were performed. The structure and properties of the synthesized nanobiocomposite were then evaluated by using analyzes such as FT-IR, EDX, FE-SEM, XRD, TGA and VSM. Purification of ALPs with chitosan-metformin/NiCl2/Fe3O4 nanobiocomposite is a fast, reusable and cost-effective method. By this protocol, 62% purification efficiency was obtained and the synthesized nanobiocomposite was not attached to other proteins in hen's egg yolk. ALPs was obtained approximately in the pure form and the purification process was evaluated using SDS-PAGE. The reusability of nanobiocomposites was evaluated and a slight decrease in adsorption capacity was observed after 4 cycles.

Fabrication of nickel magnetic nanoparticles by combination of polyol and hydrothermal processes

Nickel magnetic nanoparticles have been successfully fabricated by combination of polyol process and hydrothermal treatment. In this research, the formation of Ni nanoparticles was determined by X-ray diffraction (XRD) and Ultraviolet–visible spectroscopy (UVVis). The morphology and size of nanoparticles were observed by using Transmission Electron Microscopy (TEM) while magnetic property of Ni nanoparticles have been characterized by vibrating sample magnetometer (VSM). The results indicate that the synthesized Ni nanoparticles are in spherical shape and the sizes of nanoparticles are in range from 3.1 nm to 5.7 nm depending on concentration of Ni2+ ions. The magnetization study in nickel nanoparticles shows ferromagnetic interaction but close to superparamagnetic state and the magnetization decreases with the size reduction.

Preparation and characterization of magnetic nickel nanoparticles by chemical reduction reaction

The efficiency of many of conversion-processes in petroleum and industrial improves upon application of materials with the nanosized scale dimension, which is caused by enhancements and advances of improved properties as the particle size decreases. Nickel nanoparticles has numerous applications in petroleum industry with its own catalytic in additional to the magnetic properties. In this study, high purity nanosized magnetic nickel particles has been effectively prepared by chemical reduction of nickel chloride using hydrazine hydrate as reducing agent in aqueous solutions containing ethylene glycol and water and using polyvinylpyrrolidone (PVP) as anti-agglomeration agent. Nanosized Ni particles samples with different hydrazine to nickel chloride mole ratios and PVP to nickel chloride ratios were obtained at constant temperature of 80 °C.&#x0D; The morphology and structural properties of the produced magnetic nickel nanoparticles were characterized by powder XRD and AFM methods. XRD study revealed that the prepared nanoparticles were pure nickel nanoparticles without considerable oxides or other impurity phases. AFM test revealed that all prepared Ni nanoparticles was in nano scale, it was stated that Ni nanoparticles size was very affected by the hydrazine/nickel mole ratio. Experimental results showed that particle size decreases from 94.35 nm to 71.48 nm when increases the [N2H4]/[Ni2+] molar ratio from 15:1 to 45:1.

Flexible 3D porous graphene film decorated with nickel nanoparticles for absorption-dominated electromagnetic interference shielding

Electromagnetic interference (EMI) shielding materials are vital for aerospace, military and portable wearable electronic equipment. Developing a high performance absorption-dominated EMI shielding materials with flexibility and lightness remains a challenge. Herein, we report an EMI shielding flexible thin-film composed of a 3D laser induced graphene (LIG) on polyimide substrate and magnetic nickel nanoparticles (Ni NPs) decorated in the porous LIG network. The 3D pore structure and interconnected conductive network ​​of LIG can cause the dielectric loss and multiple internal reflection dissipation of incident electromagnetic waves. Combined with the magnetic loss effect of Ni NPs, the composite thin-film exhibits ultra-efficient absorption-dominated EMI shielding performance. The EMI shielding effectiveness (SE) of a single layer optimized composite thin-film is 55 dB in the X-band (8.2–12.4 GHz) with absorption rate of 82%. The composite thin-film also possesses high flexibility with 89% EMI SE retention after 500 bendings. Furthermore, double layered composite film with thickness of only 0.327 mm can be easily prepared on both side of the polyimide substrate, exhibiting EMI SE as high as 79 dB with the absorption rate of 86%, which is superior than most of carbon- and Ni-based EMI shielding materials. Our findings may pave the way for designing high performance flexible absorption-dominated EMI shielding materials.

Magnetization of graphene oxide nanosheets using nickel magnetic nanoparticles as a novel support for the fabrication of copper as a practical, selective, and reusable nanocatalyst in C-C and C-O coupling reactions.

Catalyst species are an important class of materials in chemistry, industry, medicine, and biotechnology. Moreover, waste recycling is an important process in green chemistry and is economically efficient. Herein, magnetic graphene oxide was synthesized using nickel magnetic nanoparticles and further applied as a novel support for the fabrication of a copper catalyst. The catalytic activity of supported copper on magnetic graphene oxide (Cu–ninhydrin@GO–Ni MNPs) was investigated as a selective, practical, and reusable nanocatalyst in the synthesis of diaryl ethers and biphenyls. Some of the obtained products were identified by NMR spectroscopy. This nanocatalyst has been characterized by atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM), wavelength dispersive X-ray spectroscopy (WDX), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometer (VSM) techniques. The results obtained from SEM shown that this catalyst has a nanosheet structure. Also, XRD and FT-IR analysis show that the structure of graphene oxide and nickel magnetic nanoparticles is stable during the modification of the nanoparticles and synthesis of the catalyst. The VSM curve of the catalyst shows that this catalyst can be recovered using an external magnet; therefore, it can be reused several times without a significant loss of its catalytic efficiency. The heterogeneity and stability of this nanocatalyst during organic reactions was confirmed by the hot filtration test and AAS technique.

Nano-sized magnetic Ni particles based dispersive solid-phase extraction of trace Cd before the determination by flame atomic absorption spectrometry with slotted quartz tube: a new, accurate, and sensitive quantification method.

In this study, a new analytical strategy was developed to determine trace cadmium in aqueous samples with high sensitivity and accuracy. A combination of magnetic nickel nanoparticles (Ni-MNPs) based dispersive solid-phase extraction (DSPE) and flame atomic absorption spectrometry fitted with a slotted quartz tube (SQT-FAAS) lowered the detection limit of cadmium. The magnetic Ni nanoparticles were synthesized, characterized, and thoroughly optimized in a stepwise approach. The quartz tube was custom cut in the laboratory to suit the specifics of the flame burner. Using the optimized conditions, a limit of detection value of 0.58 μg/L and limit of quantification value of 1.93 μg/L were obtained. To demonstrate accuracy and applicability of the developed method, well water samples were analyzed for their Cd content, and matrix effect on the extraction yield was investigated. The percent recovery results calculated ranged from 93.8 to 108.2%, with corresponding standard deviation values ranging from 1.7 to 7.7. These results established the developed method as sensitive, accurate, and precise for determination of cadmium at trace levels.

Synthesis of nickel nanoparticles by a green and convenient method as a magnetic mirror with antibacterial activities

In this work, a simple protocol was described for the synthesis of nickel magnetic mirror nanoparticles (NMMNPs) including antibacterial activities. The identification of NMNPs was carried out by field-emission scanning electron microscopy (FESEM) images, energy-dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) pattern, transmission electron microscopy (TEM) images and vibrating sample magnetometer (VSM) curve. The antibacterial activities are investigated against S. aureus and E. coli as the Gram-positive and Gram-negative bacteria, respectively. The UV–Vis absorption was also studied in the present of NMMNPs at different time intervals that disclosed decreasing of the bacterial concentration. More than 80% of the bacteria were disappeared after treating in the presence of NMMNPs for 18 h. The Ni-NPs revealed an excellent mirror attribute with a well-controlled transmission (7%). A better light-reflectivity over conventional glass or a mercury mirror proved their utility for domestic uses in comparison with conventional mirrors as rather toxic materials like mercury. Owing to its magnetic properties, this kind of mirror can be easily made onto glass by using an external magnet. An ordered crystalline structure, admissible magnetic properties, substantial antibacterial activities, tunable mirror properties, mild reaction conditions, and overall, the facile synthesis are the specific features of the present protocol for the possible uses of NMMNPs in diverse applications.

Influence of uniform magnetic field on elastic modulus in polyacrylamide ferrogels with embedded nickel nanoparticles

Polyacrylamide ferrogels with embedded nickel magnetic nanoparticles were synthesized by radical polymerization in water. The elastic modulus of ferrogels was measured under unidirectional compression in a uniform magnetic field with a strength of 0, 165, 220 and 275 Oe. With an increase in the content of nickel particles in ferrogel from 0 to 5.3% by weight, the elastic modulus in zero magnetic field increased by 60%. The application of magnetic field parallel to the direction of compression resulted in the increase of modulus, and if the field was applied perpendicular to the compression, the modulus tends to decrease. Such trends are in good agreement with the features of magnetostriction of a non-compressible uniformly magnetized sphere in a constant magnetic field.

Fabrication of Nickel NanoChains/PVDF Nanocomposites and Their Electrical/Magnetic Properties

Magnetic nickel nanoparticles (NPs) and nanochains (NNCs) are grown in a polyol medium under a static field as an alternative to template electrodeposition and strong reducers. Scanning electron microscopy (SEM) images and their statistical analysis show an important aspect ratio of 75 for NNCs. These NNCs present enhanced magnetic properties in terms of coercive field (HC = 163 Oe) and saturation magnetization (MS = 10.8 emu g−1). Nanocomposites of NNCs/PVDF are fabricated with 2 %vol. NNCs and present better properties than NPs/PVDF with higher filler content. The longitudinal and transverse magnetic properties of the composite are measured showing that higher properties are recorded in the longitudinal direction. Electrical conductivity of composite is plotted as a function of NNCs volume content to determine the electrical percolation threshold. The corresponding value of the apparent aspect ratio (ξ = 70) confirms that the processing of composite does not modify the particles morphology. Thus, it explains the enhancement of the magnetic properties due to the NNCs anisotropy.

Elastomagnetic NI-PDMS nanofibers via coaxial electrospinning

Electrospun nanofibres were prepared starting from a dispersion of Nickel magnetic nanoparticles (MNPs) in Polydimethylsiloxane (PDMS) and Tetrahydrofurane (THF). Coaxial electrospinning was used to realize a temporary structure which wraps PDMS fibers into a thin shell of PolyvynilPirollidone (PVP), in which the crosslinking reaction of the inner fiber core is completed. After the removal of the PVP shell, the fiber skeins exhibit remarkable elastomagnetic deflection induced by transversal magnetization. The proposed methodology could potentially open up really intriguing perspectives in the fabrication of devices—deformable by magnetic forces—for bio-electronics and bio-medical applications.

Magnetic properties of cellulose‐grafted reduced graphite oxide decorated with Ni nanoparticles

We report the immobilization of nickel nanoparticles on the surface of cellulose‐grated reduced graphite oxide sheets (rGO). The decoration of GO with magnetic nickel nanoparticles was conducted in three steps. First, pure graphite oxide (GO) was functionnalized by cellulose. Then, the corresponding material was doped with Ni nanoparticles (NiNPs) using NiCl2.6H2O followed by a chemical reduction in presence of hydrazine. The resulting NiNPs/cellulose‐grafted rGO material with a 20 wt% NiNPs content was found to be nearly ferroramagnetic. POLYM. ENG. SCI., 58:1630–1635, 2018. © 2017 Society of Plastics Engineers

Formation of nickel magnetic nanoparticles and modification of nickel phthalocyanine matrix by sodium doping

Data for the vapor-phase doping (300°C) of nickel phthalocyanine (NiPc) by sodium taken in different concentrations (x), as well as structural analysis data for Na x = 0.2NiPc, Na x = 1NiPc, and Na x = 3NiPc samples, have been reported. The structure of the samples and their atomic configuration versus the doping level have been studied by transmission electron microscopy, Raman scattering, X-ray diffraction, X-ray absorption spectroscopy, and extended X-ray absorption fine structure (EXAFS) spectroscopy. The structural parameters of Ni–N, Ni–C, and Ni–Ni bonds have been determined, and it has been found that, at a low level of doping by sodium, local structural distortions are observed in some molecules of the NiPc matrix near nickel atoms. The fraction of these molecules grows as the doping level rises from x = 0.2 to x = 1.0. It has been shown that doping changes the oscillation mode of light atoms, which indicates a rise in the electron concentration on five- and six-membered rings. At a high level of sodium doping (x = 3.0), nickel nanoparticles with a mean size of 20 nm and molecule decomposition products have been observed in the NiPc matrix. It has been found that the fraction of nickel atoms in the Na x = 3NiPc nanoparticles as estimated from EXAFS data is sufficient for the room-temperature magnetic properties of the samples to persist for a long time.

Fabrication of nanoscale to macroscale nickel-multiwall carbon nanotube hybrid materials with tunable material properties

To utilize their superior properties, multiwall carbon nanotubes (MWNTs) must be manipulated and aligned end-to-end. We describe a nondestructive method to magnetize MWNTs and provide a means to remotely manipulate them through the electroless deposition of magnetic nickel nanoparticles on their surfaces. The noncovalent bonds between Ni nanoparticles and MWNTs produce a Ni-MWNT hybrid material (NiCH) that is electrically conductive and has an enhanced magnetic susceptibility and elastic modulus. Our experiments show that MWNTs can be plated with Ni for Ni:MWNT weight ratios of γ = 1, 7, 14 and 30, to control the material properties. The phase, atom-level, and morphological information from x-ray diffraction, energy dispersive x-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, dark field STEM, and atomic force microscopy clarify the plating process and reveal the mechanical properties of the synthesized material. Ni metalizes at the surface of the Pd catalyst, forming a continuous wavy layer that encapsulates the MWNT surfaces. Subsequently, Ni acts as an autocatalyst, allowing the plating to continue even after the original Pd catalyst has been completely covered. Raising γ increases the coating layer thickness from 10 to 150 nm, which influences the NiCH magnetic properties and tunes its elastic modulus from 12.5 to 58.7 GPa. The NiCH was used to fabricate Ni-MWNT macrostructures and tune their morphologies by changing the direction of an applied magnetic field. Leveraging the hydrophilic Ni-MWNT outer surface, a water-based conductive ink was created and used to print a conductive path that had an electrical resistivity of 5.9 Ω m, illustrating the potential of this material for printing electronic circuits.

Super magnetic nanoparticles NiFe2O4, coated with aluminum–nickel oxide sol-gel lattices to safe, sensitive and selective purification of his-tagged proteins

Super magnetic nanoparticle NiFe2O4 with high magnetization, physical and chemical stability was introduced as a core particle which exhibits high thermal stability (>97%) during the harsh coating process. Instead of multi-stage process for coating, the magnetic nanoparticles was mineralized via one step coating by a cheap, safe, stable and recyclable alumina sol-gel lattice (from bohemite source) saturated by nickel ions. The TEM, SEM, VSM and XRD imaging and BET analysis confirmed the structural potential of NiFe2O4@NiAl2O4 core–shell magnetic nanoparticles for selective and sensitive purification of His-tagged protein, in one step. The functionality and validity of the nickel magnetic nanoparticles were attested by purification of three different bioactive His-tagged recombinant fusion proteins including hIGF-1, GM-CSF and bFGF. The bonding capacity of the nickel magnetics nanoparticles was studied by Bradford assay and was equal to 250 ± 84 μg Protein/mg MNP base on protein size. Since the metal ion leakage is the most toxicity source for purification by nickel magnetic nanoparticles, therefor the nickel leakage in purified final protein was determined by atomic absorption spectroscopy and biological activity of final purified protein was confirmed in comparison with reference. Also, in vitro cytotoxicity of nickel magnetic nanoparticles and trace metal ions were investigated by MTS assay analysis. The results confirmed that the synthesized nickel magnetic nanoparticles did not show metal ion toxicity and not affected on protein folding.