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1.
《Electrochemistry communications》2007,9(10):2606-2610
Nano-sized nickel ferrite (NiFe2O4) was prepared by hydrothermal method at low temperature. The crystalline phase, morphology and specific surface area (BET) of the resultant samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and nitrogen physical adsorption, respectively. The particle sizes of the resulting NiFe2O4 samples were in the range of 5–15 nm. The electrochemical performance of NiFe2O4 nanoparticles as the anodic material in lithium ion batteries was tested. It was found that the first discharge capacity of the anode made from NiFe2O4 nanoparticles could reach a very high value of 1314 mAh g−1, while the discharge capacity decreased to 790.8 mAh g−1 and 709.0 mAh g−1 at a current density of 0.2 mA cm−2 after 2 and 3 cycles, respectively. The BET surface area is up to 111.4 m2 g−1. The reaction mechanism between lithium and nickel ferrite was also discussed based on the results of cycle voltammetry (CV) experiments. 相似文献
2.
《Journal of Saudi Chemical Society》2021,25(12):101388
A facile strategy was used for the synthesis of nickel ferrite/zinc oxide (NiFe2O4/ZnO) nanocomposite via an ultra-sonication method and observed its recyclability and photostability with enhanced visible light-driven photocatalytic performance. The photo degradation activities of as-synthesized photocatalysts were investigated using various dyes including methylene blue, crystal violet and methyl orange under solar light irradiation. Prepared material degrades 49.2% methyl orange, 44.4% methyl blue and 41.3% crystal violet in 40 min. Further, the synergistic effect of nickel ferrite and zinc oxide can reduce the probability of recombination of charge carrier and boost the charge separation which leads to remarkable photocatalytic performance. Magnetic properties of nickel ferrite reduces the agglomeration of material and increases the recyclability. The NiFe2O4/ZnO nanocomposites also exhibited better antibacterial activity for Pseudomonas aeruginosa and Staphylococcus aureus, which shows that they can be used for both environmental and biological applications. 相似文献
3.
This paper deals with the simultaneous removal of sulfur from commercial kerosene at room temperature using sorbents containing NiFe2O4 nanoparticles. The nanocrystalline NiFe2O4 based sorbents were prepared using the combustion route. The effect of fuel content on the surface properties and desulferization activity of Ni/Fe mixed oxide sorbents has been studied.It was observed that incorporation of metal cations (Ni2+) into the hematite (α-Fe2O3) crystal structure alters the surface properties and desulferization activity of the investigated oxides, which in turn depends on the nature and concentration of the incorporated metal cation and the released heat during the combustion process. The effect of fuel content in modifying the resultant surface area could be directly related to the variations in the rate of crystal growth of the solids studied depending upon preparation temperature. Interestingly, all the prepared ferrites exhibit a narrow pore size distribution in the range of 0.9–2 nm. The capacity of NiFe2O4 to adsorb sulfur from commercial kerosene was evaluated in terms of their textural and chemical characteristics. 相似文献
4.
《Arabian Journal of Chemistry》2020,13(1):783-798
This study reports facile in situ synthesis of magnetically retrievable nanocomposites of nanocellulose (derived from waste biomass) and NiFe2O4 nanoparticles using hydrothermal method. The synthesized nanocomposites were characterized using various techniques such as FT-IR, powder XRD, HR-TEM, BET and VSM. The characterization of nanocomposites clearly revealed that NiFe2O4 nanoparticles were well dispersed on the surface of cellulose nanofibres. The catalytic performance of the synthesized nanocomposites was assessed for both the photocatalytic oxidation and reduction of organic pollutants. The prepared nanocomposites displayed excellent catalytic performance in comparison to pristine NiFe2O4 nanoparticles due to stabilization and increased dispersability of NiFe2O4 nanoparticles on the cellulose matrix. The present work promotes the use of bio based renewable sources to fabricate environment friendly materials to be used in the field of catalysis for the abatement of organic pollutants. 相似文献
5.
V. Hajdu M. Varga G. Muránszky G. Karacs F. Kristály B. Fiser B. Viskolcz L. Vanyorek 《Materials Today Chemistry》2021
Cobalt, copper, and nickel ferrite spinel nanoparticles have been synthesized by using a combination of sonochemical treatment and combustion. The magnetic nanoparticles have been used as supports to prepare ~4 wt% palladium catalysts. The ferrites were dispersed in an ethanolic solution of Pd(II) nitrate by ultrasonication. The palladium ions were reduced to metallic Pd nanoparticles, which were then attached to the surface of the different metal oxide supports. Thus, three different catalysts (Pd/CoFe2O4, Pd/CuFe2O4, Pd/NiFe2O4) were made and tested in the hydrogenation of 2,4-dinitrotoluene (DNT). A possible reaction mechanism, including the detected species, has been envisaged based on the results. The highest 2,4-diaminotoluene (TDA) yield (99 n/n%) has been achieved by using the Pd/NiFe2O4 catalyst. Furthermore, the TDA yield was also reasonable (84.2 n/n%) when the Pd/CoFe2O4 catalyst was used. In this case, complete and easy recovery of the catalyst from the reaction medium is ensured, as the ferrite support is fully magnetic. Thus, the catalyst is very well suited for applicationy in the hydrogenation of DNT or other aromatic nitro compounds. 相似文献
6.
Nanocomposite based on epoxy and MWCNTs modified with NiFe2O4 nanoparticles as efficient microwave absorbing material
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In order to make a microwave absorbent material with good dielectric and magnetic properties, well dispersed microwave absorbing hybrid epoxy polymer composites containing nickel doped Fe3O4 nanocrystals coated on carbon nanotubes (NiFe2O4‐MWCNTs/epoxy) were synthesized by the combined precipitation‐hydrothermal method in 1‐30 wt.% of nanoparticles. Nickel possess well interaction with microwave radiation and represents fine electromagnetic interference (EMI) shielding and by dopping it into ferrite spinel structures, does not show any tendency to oxidation. Well‐dispersed NiFe2O4–MWCNTs/epoxy nanocomposite prepared by new in‐situ polymerization method. First, NiFe2O4–MWCNT nanoparticles ultrasonicated in acetone and after mixing with epoxy resin ultrasonicated again. Finally, hardner added to the composite and tuned temperature for evaporating solvent. X‐ray diffraction (XRD) and energy dispersive spectroscopy (EDS) confirmed the synthesizing NiFe2O4 nanoparticles. Saturation magnetization value of NiFe2O4‐MWCNTs is about 29 emu/g with very low remanence and coercivity content, which revealed that the NiFe2O4‐MWCNTs is ferromagnetic nanocrystal. Transmission electron microscopy (TEM) used to characterize the distribution of NiFe2O4 nanocrystals on the surface of MWCNTs. The TEM images show that NiFe2O4 nanocrystals have a mean size of 12 nm, and completely coated on the exterior surface of MWCNTs. The obtained results of reflection loss revealed that the maximum values of reflection loss of the NiFe2O4‐MWCNTs/epoxy increase by enhancing the content of nanoparticles until 10 wt.% and decreases in 30 wt.%. 相似文献
7.
《Arabian Journal of Chemistry》2023,16(1):104386
In this study, gold nanoparticles (AuNPs) were green synthesized using plant extract. The obtained nanoparticles (Au NPs) were characterized by advanced physical and chemical techniques like TEM, FTIR, UV–vis, SEM, XRD and EDX. SEM image displayed the quasi-spherical shaped nanoparticles of mean diameter 20–50 nm. All the particles were of uniform shape and texture. From the XRD pattern, four distinct diffraction peaks at 38.2°, 44.2°, 64.7° and 77.4° are indexed as (1 1 1), (2 0 0), (2 2 0) and (3 1 1) planes of fcc metallic gold. The in vitro cytotoxic and anti-gastric carcinoma effects of biologically synthesized Au NPs against cancer cell lines were assessed. The IC50 of the Au NPs were 192, 149, 76 and 85 µg/mL against NCI-N87, MKN45, GC1401 and GC1436 gastric cancer cell lines. The anti-gastric carcinoma properties of the Au NPs could significantly remove the cancer cell lines in a time and concentration-dependent manner. So, the findings of the recent research show that biologically synthesized Au NPs might be used to cure cancer. 相似文献
8.
Changjoon Yoon Kyoungah Cho Jae-Hyun Lee Dongmok Whang Byung-Moo Moon Sangsig Kim 《Solid State Sciences》2010,12(5):745-749
P-type Si nanowire (NW)-based nano-floating gate memory (NFGM) with Au nanoparticles (NPs) embedded in Al2O3 gate layers is characterized in this study. The electrical characteristics of a representative p-type Si NW-based NFGM exhibit a counterclockwise hysteresis loop indicating the trapping and detrapping of electrons in the Au NP nodes of the NFGM device. The threshold voltage shift of the device is 5.4 V and the device has good retention over a lapse of time of 5 × 104 s. On the other hand, the p-type Si NW-based top-gate device without any Au NPs does not exhibit any significant threshold voltage shift. This observation reveals that the memory behavior of the p-type Si NW-based NFGM is due to the trapping and detrapping of charge carriers in the Au NPs. 相似文献
9.
Yongbo Li Ran Yi Aiguo Yan Lianwen Deng Kechao Zhou Xiaohe Liu 《Solid State Sciences》2009,11(8):1319-1324
We demonstrated that ZnFe2O4/polypyrrole core-shell nanoparticles could be facilely synthesized via in situ chemical oxidative polymerization of pyrrole monomers on the surface of ZnFe2O4 nanoparticles. The shell thickness of core-shell nanoparticles could be easily controlled by adjusting the amount of pyrrole monomers. The phase structures, morphologies and properties of the as-prepared products were investigated by XRD, TEM, SEM, VSM, and FTIR spectra. Magnetic studies revealed that the saturation magnetization (Ms) and coercivity (Hc) of ZnFe2O4/PPy core-shell nanoparticles is 17.8 emu/g and 130 Oe, respectively. The electromagnetic characteristics of products showed that ZnFe2O4/PPy core-shell nanoparticles exhibit excellent microwave absorption performance than ZnFe2O4 nanoparticles, such as more powerful absorbing property and wider electromagnetic wave absorbing frequency band due to the proper matching of the permittivity and the permeability of ZnFe2O4/PPy core-shell nanoparticles. 相似文献
10.
《Comptes Rendus Chimie》2014,17(4):352-358
Using solid complex molecular precursor [bis(salicylaldehyde)ethylenediiminecobalt(II)], [Co(salen)], a simple and surfactant-free method to synthesize Co3O4 nanoparticles was proposed. Cubic-phase Co3O4 nanoparticles of size 30–50-nm could be produced by thermal treatment of the Co(salen) in the air at 500 °C for 5 h. The as-prepared samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical absorption spectrum indicates that the direct band gaps of Co3O4 nanoparticles are 1.53 and 2.02 eV. The optical property test indicates that the absorption peak of the nanoparticles shifts towards short wavelengths, and the blue shift phenomenon might be ascribed to the quantum effect. The hysteresis loops of the obtained samples reveal their ferromagnetic behavior, an enhanced coercivity (Hc) and a decreased saturation magnetization (Ms) as compared to their respective bulk materials. 相似文献
11.
《Journal of Saudi Chemical Society》2023,27(5):101689
This research work includes the fabrication of iron oxide nanoparticles (Fe2O3 NPs) by green construction approach using Wisteria sinensis leaves extract. Due to its eco-friendly approach, the synthesis of iron oxide NPs (Fe2O3 NPs) using various plant sources, such as plant parts, and microbial cells have gained a lot of attention in recent years. Cost-effectiveness and ease of availability make Wisteria sinensis leaves extract a potential candidate for the construction of iron oxide NPs. The various key features like biocompatibility, non-toxicity capping, and stabilizing agents present in biological sources are advantageous for usage in a variety of applications. The phytoconstituents present in the leaf extract of Wisteria sinensis serve as reducing and stabilizing agents. The biologically fabricated (Fe2O3 NPs) were analyzed using FT-IR, XRD, UV–vis spectroscopy, and SEM. In the present work, the antioxidant and photocatalytic dye degradation efficiency of Fe2O3 NPs has been studied. The dye degradation efficiency of methylene blue dye was found to be 87% at 180 min upon exposure to sunlight. The capacity of Fe2O3 NPs to scavenge 2,2-diphenyl-1-picrylhydrazyl hydrate free radicals (DPPH) was examined using a UV–Vis spectrophotometer. The study compared the radical scavenging activity (RSA) of Fe2O3 nanoparticles (NPs) with that of the standard antioxidant ascorbic acid. The results demonstrated that Fe2O3 NPs have a greater ability to scavenge radicals than ascorbic acid. The half-maximal inhibitory concentration (IC50) of Fe2O3 NPs was observed to range from 0.12 to 0.17. Furthermore, Fe2O3 NPs displayed the highest antifungal activity, with an inhibition zone of 26.8 mm against F. oxysporum. These findings suggest that the biologically synthesized Fe2O3 NPs possess potent antimicrobial and dye degradation properties. 相似文献
12.
《Supramolecular Science》1998,5(3-4):227-228
Embedding structures of a metal nanoparticle in an oxide matrix were first achieved by electron beam irradiation. In the system of Al/α-Al2O3. Al nanoparticles derived from θ-Al2O3 migrated and embedded in α-Al2O3 matrix having epitaxy relation, {1 1 2̄ 0}α-Al2O3//{2 0 0} Al. The driving force of the embedding is momentum transfer from electrons or ions to Al atoms of nanoparticles in the pole piece of transmission electron microscopy. 相似文献
13.
Nano-sized nickel ferrite (NiFe2O4) and cobalt ferrite particles (CoFe2O4) were successfully synthesized using a hydrothermal method. Techniques of X-ray diffraction, scanning electron microscope, Fourier transform infrared spectrometer, energy dispersive X-ray spectroscopy, vibrating sample magnetometer and transmission electron microscope have been used to characterize and study the as-synthesized NiFe2O4 and CoFe2O4 products. The results showed that the average size of the nickel and cobalt ferrite nanoparticles is smaller than 10 and 100 nm, respectively. The results of magnetic measurement showed that the synthesized NiFe2O4 and CoFe2O4 nanoparticles were superparamagnetic and soft ferromagnetic materials, respectively. Study of adsorption behavior showed that these nanoparticles can act as a good adsorbent for removing Pb2+. 相似文献
14.
Marccus Victor Almeida Martins Clarissa Bonfim Welter Cantanhêde da Silva Frank Nelson Crespilho 《Electrochemistry communications》2010,12(11):1509-1512
In this paper, we discuss the synthesis and electrochemical properties of a new material based on iron oxide nanoparticles stabilized with poly(diallyldimethylammonium chloride) (PDAC); this material can be used as a biomimetic cathode material for the reduction of H2O2 in biofuel cells. A metastable phase of iron oxide and iron hydroxide nanoparticles (PDAC–FeOOH/Fe2O3-NPs) was synthesized through a single procedure. On the basis of the Stokes–Einstein equation, colloidal particles (diameter: 20 nm) diffused at a considerably slow rate (D = 0.9 × 10? 11 m s? 1) as compared to conventional molecular redox systems. The quasi-reversible electrochemical process was attributed to the oxidation and reduction of Fe3+/Fe2+ from PDAC–FeOOH/Fe2O3-NPs; in a manner similar to redox enzymes, it acted as a pseudo-prosthetic group. Further, PDAC–FeOOH/Fe2O3-NPs was observed to have high electrocatalytic activity for H2O2 reduction along with a significant overpotential shift, ΔE = 0.68 V from ? 0.29 to 0.39 V, in the presence and absence of PDAC–FeOOH/Fe2O3-NPs. The abovementioned iron oxide nanoparticles are very promising as candidates for further research on biomimetic biofuel cells, suggesting two applications: the preparation of modified electrodes for direct use as cathodes and use as a supporting electrolyte together with H2O2. 相似文献
15.
Shuiying Gao Daqiang Yuan Jian Lü Rong Cao 《Journal of colloid and interface science》2010,341(2):320-325
The layer-by-layer (LbL) assembled thin films containing tetraamino-thiacalix[4]arenes (1) and tetraamino-calix[4]arenes (2) were used as nanoreactor to synthesize in situ Ag nanoparticles (Ag NPs). UV–vis spectra and AFM images demonstrate that Ag NPs are included in the (1/Ag NPs)n and (2/Ag NPs)n multilayer films. The silver ions are absorbed through cation–π interaction and calix[4]arene-metal ion coordination interaction and are reduced into Ag NPs by calix[4]arenes. TEM images indicated that Ag NPs within aminocalix[4]arene multilayers were highly dispersed and uniform. Moreover, the mean size of Ag NPs is smaller than 10 nm. 相似文献
16.
Johanna S. Knyrim S. Rebecca Römer Wolfgang Schnick Hubert Huppertz 《Solid State Sciences》2009,11(2):336-342
The new orthorhombic barium borate β-BaB4O7 was synthesized under high-pressure/high-temperature conditions in a Walker-type multianvil apparatus at 7.5 GPa and 1100 °C, starting from stoichiometric mixtures of the binary oxides. β-BaB4O7 crystallizes in space group Pmnb with Z = 2 and lattice parameters a = 1099.4(2), b = 901.7(2), c = 430.73(9) pm, R1 = 0.0199, and wR2 = 0.0406 (all data). The network-structure is built up exclusively from BO4-tetrahedra, linked via common corners. Its structural differences to the ambient-pressure phase α-BaB4O7 and structural agreements with the isotypic high-pressure phases β-MB4O7 (M = Ca, Hg, Sn) and the ambient-pressure phases MB4O7 (M = Sr, Pb, Eu) are discussed. β-BaB4O7 and a hypothetical BaB4O7 in the β-MB4O7 (M = Ca, Hg, Sn) structure were studied as high-pressure phases of α-BaB4O7, using density functional calculations. The transition pressure of α-BaB4O7 into the structure of β-BaB4O7 was calculated to 1.5 GPa; the transition pressure of β-BaB4O7 into BaB4O7 in the β-MB4O7 (M = Ca, Hg, Sn) structure to 7.5 GPa. 相似文献
17.
《Arabian Journal of Chemistry》2019,12(4):489-502
The present work reports the influence of the nanoadditives Y2O3, Gd2O3, and CaO on the magnetic, electrical and dielectric properties of sintered nanoferrites Co0.2Ni0.3Zn0.5Fe2O4. All powders were synthesized via the polyol method. XRD analysis showed that except the nanoferrite which was obtained by in an one-post procedure, subsequent calcinations of the as-produced additives were necessary to obtain nanocrystals of the desired phases. The mean particle size inferred from TEM images of the nanoadditives sintered at 1000 °C ranges from 87 nm for Y2O3 to 126 nm for CaO. IR spectroscopy provided useful information on the nature of the core and the surface chemistry of the as-produced additives and their associated annealed powders. Upon sintering, it was found that the incorporation of 5 wt.% additives remarkably increased the densification of the doped materials. The most important increase in densification was observed with CaO due to its larger particles. dc M-H hysteresis loops taken at 300 K revealed a superparamagnetic behavior of the produced ferrite/nanoadditives. Additionally, as expected, the ferrite/nanoadditives showed reasonable saturation magnetization and high Curie temperature. The electrical and dielectric properties, namely the resistivity, the loss factor, and the relation frequency were found to be clearly affected by doping. The resistivity decreased with increasing temperature indicating a semiconducting behavior. Further, at room temperature, the highest resistivity was observed with Y2O3. The major role was attributed to the high fraction of insulating Y2O3 owing to its smallest particles combined with the low Fe2+ concentration in the ferrite nanoparticles taking advantages of the moderate sintering temperature. In addition, the dc conductivity was found to follow the Arrhenius law with a slope change observed at the Curie temperature. Further, all the additives clearly affected the ac conductivities of the pure ferrite. The variation of the dielectric permittivity with frequency and temperature was explained on the basis of M-W type of interfacial polarization. Additionally, at high frequencies, the lower dielectric loss was found with Y2O3 doping. It was found to be of about 10 times lower than the undoped material and much larger than reported for similar undoped bulk ferrites. 相似文献
18.
Yan Lu Yong Wang Yuqin Zou Zheng Jiao Bing Zhao Yaqin He Minghong Wu 《Electrochemistry communications》2010,12(1):101-105
This paper reports the microwave-assisted synthesis of Co3O4 nanomaterials with different morphologies including nanoparticles, rod-like nanoclusters and macroporous platelets. The new macroporous platelet-like Co3O4 morphology was found to be the best suitable for reversible lithium storage properties. It displayed superior cycling performances than nanoparticles and rod-like nanoclusters. More interestingly, excellent high rate capabilities (811 mAh g?1 at 1780 mA g?1 and 746 mAh g?1 at 4450 mA g?1) were observed for macroporous Co3O4 platelet. The good electrochemical performance could be attributed to the unique macroporous platelet structure of Co3O4 materials. 相似文献
19.
Yong Liu Yuchun Song Yaohui You Xiaojing Fu Jing Wen Xiaogang Zheng 《Journal of Saudi Chemical Society》2018,22(4):439-448
Spinel structure nickel ferrite (NiFe2O4) doped graphitic carbon nitride (g-C3N4) photocatalyst NiFe2O4/g-C3N4 was synthesized by the coprecipitation route to enhance the photocatalytic activity for the visible-light driven degradation of methyl orange. The NiFe2O4 doping content is responsible for the microstructure and photocatalytic activity of NiFe2O4/g-C3N4 samples. Compared with pure NiFe2O4 and g-C3N4, the 2-NiFe2O4/g-C3N4 composite with NiFe2O4 doping of 2.0 wt% exhibited excellent photocatalytic activity and superior stability after five runs for degrading methyl orange under visible light irradiation. The catalytic activity of 2-NiFe2O4/g-C3N4 sample produced using the coprecipitation route was higher than those of conventional 2-NiFe2O4/g-C3N4 bulks prepared by the impregnation approach. The prepared samples for the photocatalytic degradation of methyl orange followed pseudo-first-order reaction kinetics. It’s ascribed to the synergistic effect between NiFe2O4 and g-C3N4, which can inhibit the recombination of photoexcited electron-hole pairs, accelerate photoproduced charges separation, and enhance the visible light absorption. 相似文献
20.
SrFe12O19 (SFO)/Ni0.5Zn0.5Fe2O4 (NZFO) composite ferrite nanofibers with diameters about 120 nm have been prepared by the electrospinning and calcination process. The SFO/NZFO composite ferrites are formed after calcined at 700 °C for 2 h and the composite nanofibers with various mass ratios obtained at 900 °C are fabricated from NZFO grains about 16–40 nm and SFO grains of 19–45 nm with a uniform phase distribution. With the SFO ferrite content increasing, the coercivity (Hc) and remanence (Mr) for the composite ferrite nanofibers initially increase, reaching maximum values of 379.8 kA/m (297 K) and 242.2 kA/m (77 K), 39.1 Am2/kg (297 K) and 53.5 Am2/kg (77 K), respectively, at a mass ratio (SFO:NZFO) of 4, and then show a reduction tendency with a further increase of the mass ratio. This enhancement in magnetic properties is attributed to the competition of the exchange–coupling interaction and the dipolar interaction in the composite nanofibers. 相似文献