Synthesis and Formation Mechanism of Hollow Carbon Spheres Containing Fe3N Nanocrystals

2009 ◽  
Vol 79-82 ◽  
pp. 1281-1284 ◽  
Author(s):  
Bo Yang Liu ◽  
De Chang Jia ◽  
Li Hua Dong ◽  
Yan Sheng Yin
Keyword(s):  
Electron Microscopy ◽  
Weight Percent ◽  
Vibrating Sample Magnetometry ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

Hollow carbon spheres containing Fe3N nanocrystals (Fe3N/HCSs) are synthesized by ferrocene and ammonium chloride in high pressure argon at 500 °C. The structure, morphology and properties of the products are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and vibrating sample magnetometry (VSM). The hollow carbon spheres have diameters of 1-10 µm and shell thickness of hundreds of nanometers. The dimensions of the acicular Fe3N nanocrystals have diameters of ca. 100 nm and lengths of 600-800 nm. The weight percent of Fe3N nanocrystals in Fe3N/HCSs is about 37.8%. The saturation magnetization value of the hollow carbon spheres containing Fe3N nanocrystals is 10.61 emu/g.

Synthesis and formation mechanism of hollow carbon spheres encapsulating magnetite nanocrystals

2008 ◽  
Vol 23 (7) ◽  
pp. 1980-1986 ◽  
Author(s):  
Boyang Liu ◽  
Dechang Jia ◽  
Haibo Feng ◽  
Qingchang Meng ◽  
Yingfeng Shao
Keyword(s):  
Electron Microscopy ◽  
Diffraction Field ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Hollow Carbon ◽  
20 Nm ◽  
Magnetite Nanocrystals ◽  
Hollow Carbon Spheres

Hollow carbon spheres encapsulating magnetite nanocrystals were obtained in high-pressure argon at 600 °C followed by hydrolysis of Fe(NH3)2Cl2 in the hollow interiors at room temperature and heat treatment in argon at 450 °C for 2 h. The structure, morphology, and properties of the products were characterized by x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The hollow carbon spheres have diameters of 1–10 μm and wall thicknesses of hundreds of nanometers; the wt% of magnetite nanocrystals in them is ∼13.2%. Equiaxed magnetite nanocrystals range in size from 15 to 90 nm, while acicular magnetite nanocrystals have diameters of ∼20 nm and lengths of 120–450 nm. The saturation magnetization value of the hollow carbon spheres encapsulating magnetite nanocrystals is 4.29 emu/g.

scholarly journals Hydrothermal Synthesis, Characterization and Exploration of Photocatalytic Activities of Polyoxometalate: Ni-CoWO4 Nanoparticles

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Photocatalytic Reactions ◽  
Cobalt Tungstate

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.

Synthesis of La2NiO4+δ Nanofibers by Electrospinning Method and their Application

2018 ◽  
Vol 281 ◽  
pp. 859-864
Author(s):  
Yan Xing ◽  
Meng Fei Zhang ◽  
Tian Jun Li ◽  
Wei Pan
Keyword(s):  
Electron Microscopy ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Mixed Conductivity ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Electrospinning Method

La2NiO4+σ nanofibers exhibiting typical Ruddlesden–Popper structure (K2NiO4) were fabricated by a facile electrospinning method. X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to analyze the structure, morphology and crystal process of the La2NiO4+σ nanofibers. For electrical properties measurement, uniaxially aligned nanofibers were directly collected and assembled into electrode. In our research, La2NiO4+σ phase forms above 873K with no impurity phase emerges during the thermal treatments. The nanofibers are smooth and uniform throughout the entire length and the grain is growing as calcination temperature increases. Furthmore, the La2NiO4+σ nanofibers own high mixed conductivity at 773K, laying good foundation for intermediate temperature solid oxide fuel cells application.

SOLVOTHERMAL SYNTHESIS OF UNIFORM MAGNETITE MICROSPHERES

2010 ◽  
Vol 03 (02) ◽  
pp. 125-129 ◽  
Author(s):  
CAIQUAN ZHANG ◽  
YALI CUI ◽  
DIDI ◽  
KUNPING YAN ◽  
CHAO CHEN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Particles ◽  
Uniform Particle Size ◽  
Scanning Electron

Facile procedures to synthesize large quantities of uniform and well dispersed magnetite particles in water were developed through a solvothermal method. Magnetite microspheres were obtained by using FeCl 3 · 6H 2 O , urea and polyethylene glycol as the starting materials in ethylene glycol at 200°C for 8 h. The samples were characterized by using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and vibrating sample magnetometry. Experimental results revealed that the particles were well dispersed with uniform particle size and diameters in the range 260 to 280 nm. The saturation magnetization value was 71.5 emu/g with negligible remanence.

Preparation and Application of Carboxyl-Functioned Magnetic Nanoparticles for Arylsulfatase Immobilization

2016 ◽  
Vol 13 (10) ◽  
pp. 7408-7415
Author(s):  
Yongxing Li ◽  
Qiong Xiao ◽  
Qin Yin ◽  
Hui Ni ◽  
Yanbing Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Sulfate Ester ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Mean Diameter ◽  
Diffraction Patterns

Arylsulfatase, one of a few enzymes that can enhance the gelling strength of agar by cleaving the sulfate ester bonds in agar, was covalently immobilized with carboxyl functioned magnetic nanoparticles (CMNPs). The resultant CMNPs and immobilized arylsulfatase were characterized by transmission electron microscopy (TEM), Dynamic Light scattering (DLS), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). The TEM result indicated that the CMNPs and immobilized arylsulfatase had a similar mean particle size of 10 nm. The arylsulfatase-CMNPs had a mean diameter of 1200 nm in aqueous solution determined by the DLS, which was much bigger than the CMNPs (433.6 nm). The different sizes demonstrated that the arylsulfatase was coated on CMNPs successfully. XRD showed that diffraction patterns of the CMNPs and arylsulfatase-CMNPs were close to the standard XRD pattern of Fe3O4. Saturation magnetizations were 52.1 emu/g for carriers and 47.9 emu/g for immobilized arylsulfatase, which indicated that the particles had superparamagnetic characteristics. The TGA revealed that the amount of arylsulfatase bound to the surface of CMNPs was 5.65%. The arylsulfatase exhibited better thermal stability and reusability after immobilization, the immobilized arylsulfatase can retain more than 50% enzyme activity up to the 9th cycle.

scholarly journals Study of α-Fe2O3@ ZnO nanoleaves: Morphological and optical study

2020 ◽  
Vol 2 (1) ◽  
pp. 118-124
Author(s):  
Parastoo Khalili ◽  
◽  
Majid Farahmandjou ◽  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Weight Percent ◽  
Optical Study ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Stretching Vibrations ◽  
Scanning Electron

In this paper, α-Fe2O4@ZnO nanoparticles (NPs) were synthesized by coprecipitation method in the presence of PVP and EG surfactants. The samples were charactrized by x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and fourier transform infrared spectroscopy (FTIR). The XRD results exhibited rhombohedral α-Fe2O3 and wurtzite structure of ZnO. The SEM images showed that the NPs changed from rod-shape to nanoleaves particles after heat treatment. The TEM studies displayed the formation of Fe2O3@ZnO core-shell of as-synthesized NPs. The stretching vibrations peaks in FTIR in the wavenumber of 532 cm-1 and 473 cm-1 ascribed to the Fe and Zn groups. The XRF data indicated decreasing of the Fe weight percent from 22 %Wt. to 25 %Wt., after heat treatment.

Encapsulation of anion-cation organo-montmorillonite in terpolymer microsphere: structure, morphology, and properties

2020 ◽  
Vol 40 (4) ◽  
pp. 321-332
Author(s):  
Yuan Lin ◽  
Yangchuan Ke ◽  
Chengcheng Yu ◽  
Xu Hu ◽  
Shichao Lu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cetyltrimethylammonium Bromide ◽  
Suspension Polymerization ◽  
X Ray Diffraction ◽  
High Permeability ◽  
X Ray ◽  
Inverse Suspension Polymerization ◽  
Transmission Electron ◽  
Structure Morphology

AbstractExfoliated organo-montmorillonite (O-Mt) layers were successfully encapsulated in a terpolymer microsphere (PAAA) of acrylamide (AM)/acrylic acid (AA)/2-acrylamido-2-methylpropanesulfonic acid (AMPS) via in situ inverse suspension polymerization, with the aid of the organic modification by cetyltrimethylammonium bromide (CTAB) and sodium lauryl sulfonate (SLS). The chemical structure and properties of the Mt were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which showed that SLS molecules successfully intercalated Mt interlayers and enhanced the thermostability of Mt. The microsphere morphologies of the polymer and its nanocomposites were detected by scanning electron microscopy (SEM). The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed that the exfoliated O-Mt dispersed in the polymer matrix. The introduction of well-dispersed O-Mt layers significantly enhanced the comprehensive performance of these microspheres, including thermostability and plugging properties. The Tmax of PAAA/1.5 wt.% O-Mt nanocomposite is increased by 46°C compared to the pure terpolymer. The plugging rate of PAAA/2.0 wt.% O-Mt reached up to 85.8%. Therefore, these selected nanocomposite microspheres can provide an effective plugging in the high-permeability layers.

Synthesis of troilite by the arc-discharge method

2000 ◽  
Vol 64 (1) ◽  
pp. 143-147
Author(s):  
Chen Daizhang ◽  
Yang Xiang
Keyword(s):  
Electron Microscopy ◽  
Arc Discharge ◽  
Carbon Fibres ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray ◽  
Reducing Conditions ◽  
Transmission Electron ◽  
Hollow Carbon ◽  
Discharge Method

AbstractTroilite is a sulfide that occurs commonly in meteorites. In the laboratory, it can be synthesized by gas-solid reaction of metallic Fe and H2S-H2 gas mixtures. In this research, the arc-discharge method was used to synthesize troilite. The resulting spherules are up to 2–3 mm in diameter and composed of troilite, pyrrhotite and metallic Fe. Nanometer-sized hollow carbon fibres and balls occur on the surface of the spherules. The features and coexisting relationships of the constituents of the spherules were studied by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the phenomenon of transformation of pyrite (FeS2) into pyrrhotite (Fe1-xS), troilite (FeS) and metallic Fe under arc-discharge reducing conditions were examined.

scholarly journals Synthesis of CuO/Co3O4Coaxial Heterostructures for Efficient and Recycling Photodegradation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
R. X. Chen ◽  
S. L. Zhu ◽  
J. Mao ◽  
Z. D. Cui ◽  
X. J. Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Wire Mesh ◽  
X Ray Diffraction ◽  
Full Spectrum ◽  
Composite Photocatalyst ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Coaxial Heterostructure

The highly efficient CuO/Co3O4composite photocatalyst with different morphologies has been synthesized directly on Cu wire mesh by controlling the composition of cobalt-containing solid precursors via a simple hydrothermal method. The structure morphology and composition of the composite photocatalyst have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectra. The photocatalytic result shows that the CuO/Co3O4coaxial heterostructure is easy to recycle and exhibit enhanced photodegradation activity for methylene blue compared to single CuO nanorod arrays under full spectrum solar light irradiation. The enhanced photocatalytic efficiency of the composite could be ascribed to the synergistic effect of CuO and Co3O4. This study provides a general and effective method in the fabrication of 1D composition NRs with sound heterojunctions that show enhancement of photocatalytic performance and facility of recycling.

scholarly journals Effect of Eu3+ Concentration on the BaAl2O4/CaAl4O7: x% Eu3+ (0 ≤ x ≤ 5.5) Mixed-Phase Nanophosphors Synthesized Using Citrate Sol-Gel Method

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bamba Mahman ◽  
Mpho Enoch Sithole
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Mixed Phase ◽  
Nanometer Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Crystallite Sizes ◽  
Gel Technique

A series of undoped mixed-phase BaAl2O4/CaAl4O7 (hereafter called BC) and doped BC: x% Eu3+ (0 < x ≤ 5.5) nanophosphors were successfully prepared by the citrate sol-gel technique. Their structure, morphology, and optical properties were studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD and SEM showed that all the BC:x% Eu3+ samples consisted of the crystalline structure of the mixed phases of both the BaAl2O4 and CaAl4O7 materials. The structure resembles more that of the BaAl2O4 than the CaAl4O7 phase. The TEM results suggest that the crystallite sizes are in the nanometer scale with rod-like particles. PL results showed multiple emission peaks located at 436, 590, 616, 656, and 703 nm, which were assigned to the intrinsic defects within the BC matrix, 5D0 ⟶ 7F1, 5D0 ⟶ 7F2, 5D0 ⟶ 7F3, and 5D0 ⟶ 7F4 transitions of Eu3+, respectively. The decay curves evidently showed that the nanophosphors have persistent luminescence. The Commission Internationale de l’Eclairage (CIE) analysis revealed that doping has tuned the emission colour from blue to orange-red. The results indicate that the Eu3+-doped samples can potentially be used in the orange/red-emitting phosphors.

Sign in / Sign up

Export Citation Format

Share Document