scholarly journals A Comparative Study of the Effect of MgO and CaCO3as Support Materials in the Synthesis of Carbon Nanotubes with Fe/Co as Catalyst

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Ezekiel D. Dikio ◽  
Albert J. Kupeta ◽  
Force T. Thema
Keyword(s):  
Carbon Nanotubes ◽  
Calcium Carbonate ◽  
Comparative Study ◽  
Magnesium Oxide ◽  
Support Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Support Materials ◽  
Transmission Electron ◽  
Synthesis Of Carbon Nanotubes

A comparative study of the effect of magnesium oxide and calcium carbonate as support material in the synthesis of carbon nanotubes using the catalyst Fe/Co is presented. The synthesized carbon nanotubes were characterized with Raman spectroscopy, scanning electron spectroscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction spectroscopy (XRD), and energy dispersive spectroscopy (EDS). The morphology of the carbon nanotubes synthesized with magnesium oxide as support material gives rise to carbon nanotubes with consistent and well-defined structure unlike that synthesized with calcium carbonate. TheID/IGratio of synthesized carbon nanotubes (CNTs) was 0.8544 for magnesium oxide supported compared to 0.8501 for calcium carbonate supported carbon nanotube.

scholarly journals Observation and Characterization of Fragile Organometallic Molecules Encapsulated in Single-Wall Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Daisuke Ogawa ◽  
Ryo Kitaura ◽  
Takeshi Saito ◽  
Shinobu Aoyagi ◽  
Eiji Nishibori ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
High Yield ◽  
Single Wall Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Single Wall Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Organometallic Molecules ◽  
X Ray Absorption

Thermally fragile tris(η5-cyclopentadienyl)erbium (ErCp3) molecules are encapsulated in single-wall carbon nanotubes (SWCNTs) with high yield. We realized the encapsulation of ErCp3with high filling ratio by using high quality SWCNTs at an optimized temperature under higher vacuum. Structure determination based on high-resolution transmission electron microscope observations together with the image simulations reveals the presence of almost free rotation of each ErCp3molecule in SWCNTs. The encapsulation is also confirmed by X-ray diffraction. Trivalent character of Er ions (i.e., Er3+) is confirmed by X-ray absorption spectrum.

Efficient synthesis of carbon nanotubes with improved surface area by low-temperature solvothermal route from dichlorobenzene

2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Gantigaiah Krishnamurthy ◽  
Sarika Agarwal
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Surface Area ◽  
Heating Temperature ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractThe synthesis of well-aggregated carbon nanotubes in the form of bundles was achieved by the catalytic reduction of 1,2-dichlorobenzene by a solvothermal approach. The use of 1,2-dichlorobenzene as a carbon source yielded a comparably good percentage of carbon nanotubes in the range of 60–70 %, at a low reaction temperature of 200°C. The products obtained were analysed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The X-ray diffraction studies implied the presence of pure, crystalline, and well-ordered carbon nanotubes. The scanning electron and transmission electron microscopic images revealed the surface morphology, dimensions and the bundled form of the tubes. These micrographs showed the presence of multi-walled carbon nanotubes with an outer diameter of 30–55 nm, inner diameter of 15–30 nm, and lengths of several hundreds of nanometers. Brunauer-Emmett-Teller-based N2 gas adsorption studies were performed to determine the surface area and pore volume of the carbon nanotubes. These carbon nanotubes exhibit a better surface area of 385.30 m2 g−1. In addition, the effects of heating temperature, heating time, amount of catalyst and amount of carbon source on the product yield were investigated.

scholarly journals A Comparative Study of Carbon Nanotubes Synthesized from Co/Zn/Al and Fe/Ni/Al Catalyst

2011 ◽  
Vol 8 (3) ◽  
pp. 1014-1021 ◽  
Author(s):  
Ezekiel Dixon Dikio
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Electron Microscope ◽  
Thermogravimetric Analysis ◽  
Catalyst System ◽  
X Ray ◽  
Transmission Electron ◽  
Catalyst Systems ◽  
Synthesis Of Carbon Nanotubes ◽  
Scanning Electron

The catalyst systems Fe/Ni/Al and Co/Zn/Al were synthesized and used in the synthesis of carbon nanotubes. The carbon nanotubes produced were characterized by Field Emission Scanning Electron Microscope(FE-SEM), Energy Dispersive x-ray Spectroscopy(EDS), Raman spectroscopy, Thermogravimetric Analysis(TGA)and Transmission Electron Microscope(TEM). A comparison of the morphological profile of the carbon nanotubes produced from these catalysts indicates the catalyst system Fe/Ni/Al to have produced higher quality carbon nanotubes than the catalyst system Co/Zn/Al.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

Synthesis of Three Dimensional Graphene/Multiwalled Carbon Nanotubes Nanocomposites Hydrogel and Investigation of their Electrochemical Properties as Electrodes of Supercapacitors

2015 ◽  
Vol 1094 ◽  
pp. 222-228
Author(s):  
Lei Zhou ◽  
Da Wei He ◽  
Hong Lu Wu ◽  
Zeng Hui Qiu
Keyword(s):  
Carbon Nanotubes ◽  
Specific Capacitance ◽  
Multiwalled Carbon Nanotubes ◽  
Synthesis Method ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene

A facile synthesis method of three dimensional reduced graphene oxide (RGO)/multiwalled carbon nanotubes (MWCNTs) hydrogel was introduced. Hydrogel samples which were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and examined by X-ray diffraction (XRD) have been used as the electrode of supercapacitor. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) were used to investigate the Supercapacitors which we have fabricated. Because MWCNTs inserting into layers of RGO homogeneously prevent the layers of RGO from stacking and enlarge the specific surface area of graphene, the specific capacitance of RGO/MWCNTs material has been greatly improved. At the current density of 0.2A/g, the specific capacitance of RGO/MWCNTs electrode is about 176F/g, which means a 52% increasement compared to which of pure RGO material electrode. And the specific capacitance of RGO/MWCNTs also achieves a good rate property.

Structure Analysis of Nanocrystalline MgO Aerogel Prepared by Sol-Gel Method

2007 ◽  
Vol 130 ◽  
pp. 203-206 ◽  
Author(s):  
Grzegorz Dercz ◽  
Lucjan Pająk ◽  
Krystian Prusik ◽  
Roman Pielaszek ◽  
Janusz J. Malinowski ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Magnesium Oxide ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Technique ◽  
Microscopy Images ◽  
Nanocrystalline Mgo

Wet gel obtained by sol-gel technique was dried in supercritical CO2 to prepare hydrated form of magnesium oxide. Calcination at 723 K under vacuum yielded nanocrystalline MgO aerogel. Structure studies were performed by X-ray diffraction, scanning and transmission electron microcopies. Electron microscopy images reveal rough, unfolded and ramified structure of solid skeleton. Specific surface area SBET was equal to 238 m2/g. X-ray pattern reveals the broadened diffraction lines of periclase, the only crystalline form of magnesium oxide. The gamma crystallite size distribution was determined using FW 5 4 / 5 1 M method proposed by R. Pielaszek. The obtained values of <R> and σ (measure of polydispersity) of particle size parameters are equal to 6.5 nm and 1.8 nm, respectively, whereas the average crystallite size estimated by Williamson-Hall procedure was equal to 6.0 nm. The obtained at Rietveld refinement Rwp, and S fitting parameters equal to 6.62% and 1.77, respectively, seem to be satisfactory due to the nanosize of MgO crystallites and because of the presence of amorphous phase.

Ni/ZrO2-CeO2 Catalysts for the Simultaneous Production of Hydrogen and Carbon Nanotubes

2011 ◽  
Vol 14 (2) ◽  
pp. 127-131
Author(s):  
M. L. Hernandez-Pichardo ◽  
M. A. Valenzuela ◽  
S. P. Paredes ◽  
P. Del Angel ◽  
J. A. Montoya De la Fuente
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Ultrasound Treatment ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Simultaneous Production ◽  
Transmission Electron ◽  
Production Of Hydrogen

The catalytic methane decomposition (CMD) using Ni/ZrO2-CeO2 catalysts for the simultaneous production of hydrogen and carbon nanotubes, was studied on samples prepared by different synthesis methods. The catalysts were synthesized by the impregnation and coprecipitation methods with or without ultrasound treatment. X-ray diffraction (XRD), Raman spectroscopy and high resolution transmission electron microscopy (HRTEM) were the main characterization techniques. It was observed that the Ni impregnated catalyst with ultrasound treatment increases significantly the production of hydrogen and carbon nanotubes in the CDM at 500 °C. The results also indicated that the synthesis of catalysts via coprecipitation generates a higher number of encapsulated Ni particles by both, the ZrO2-CeO2 support and the produced carbon at the end of the reaction.

scholarly journals Facile Synthesis of Calcium Carbonate Nanoparticles from Cockle Shells

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Kh. Nurul Islam ◽  
A. B. Z. Zuki ◽  
M. E. Ali ◽  
Mohd Zobir Bin Hussein ◽  
M. M. Noordin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Carbonate ◽  
Large Scale ◽  
Low Cost ◽  
Analytical Techniques ◽  
Variable Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

A simple and low-cost method for the synthesis of calcium carbonate nanoparticles from cockle shells was described. Polymorphically, the synthesized nanoparticles were aragonites which are biocompatible and thus frequently used in the repair of fractured bone and development of advanced drug delivery systems, tissue scaffolds and anticarcinogenic drugs. The rod-shaped and pure aragonite particles of30±5 nm in diameter were reproducibly synthesized when micron-sized cockle shells powders were mechanically stirred for 90 min at room temperature in presence of a nontoxic and nonhazardous biomineralization catalyst, dodecyl dimethyl betaine (BS-12). The findings were verified using a combination of analytical techniques such as variable pressure scanning electron microscopy (VPSEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and energy dispersive X-ray analyser (EDX). The reproducibility and low cost of the method suggested that it could be used in industry for the large scale synthesis of aragonite nanoparticles from cockle shells, a low cost and easily available natural resource.

Transformation Mechanism from Carbon Nanotubes to n-diamond

2005 ◽  
Vol 20 (6) ◽  
pp. 1485-1489 ◽  
Author(s):  
Bin Wen ◽  
Tingju Li ◽  
Chuang Dong ◽  
Junze Jin
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Iron ◽  
Atmospheric Pressure ◽  
Carbon Diffusion ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
X Ray ◽  
Transmission Electron ◽  
Phase Sequence

Nanocrystal n-diamond particles were synthesized after a pyrogenation of carbon nanotubes and colloidal Fe(OH)3 at atmospheric pressure. The product was investigated with x-ray diffraction, transmission electron microscopy, thermal gravimetric analysis, and differential thermal analysis. The results indicate that the n-diamond can be synthesized with the carbon nanotubes as carbon source. The formation mechanism of the n-diamond is suggested in this paper. With the increase of temperature and hence the carbon diffusion in iron, the phase sequence is from Fe(OH)3 into Fe2O3, α–Fe, γ–Fe, and then liquid iron. When carbon in the liquid iron is saturated, graphite separated out of the liquid iron. With the decrease of temperature, the carbon in γ–Fe is separated out, and the n-diamond nuclei form and grow.

Disodium Sulfodehydroabietate as Template for Preparation of Hydrophobic Nano-Calcium

2010 ◽  
Vol 113-116 ◽  
pp. 2212-2214
Author(s):  
Shi Ya Han ◽  
Ming Hua Zhu ◽  
Zhan Qian Song ◽  
Gui Zhen Fang ◽  
Wei Li ◽  
...  
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Fourier Transform ◽  
Calcium Carbonate ◽  
Anhydrous Calcium Chloride ◽  
X Ray Diffraction ◽  
Hydrophobic Property ◽  
Anhydrous Sodium Carbonate ◽  
X Ray ◽  
Transmission Electron

In this paper, the hydrophobic nano-calcium carbonate (CaCO3) was prepared by organic matter (the bolaform surfactant Disodium Sulfodehydroabietate as template) modifying surface structure of calcium carbonate (made by anhydrous sodium carbonate and anhydrous calcium chloride) at 40°C for 2h. The prepared hydrophobic nano-CaCO3 was characterized by means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscope (TEM) and. The nano-CaCO3 with mean particle size of 64.4 nm was obtained in the range of 0.5~1.5µm by calculation. The contact angle of nano-CaCO3 with liquid solid was 117.49°. The hydrophobic property become stronger.

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