High Production of Carbon Nanotube Bundles with Fe2O3/Al2O3 Catalyst

2014 ◽  
Vol 695 ◽  
pp. 122-126 ◽  
Author(s):  
Shazia Shukrullah ◽  
Norani Muti Mohamed ◽  
Maizatul Shima Shaharun
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Chemical Vapor ◽  
Precipitation Method ◽  
High Yield ◽  
Outer Diameter ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Black Spots ◽  
Co Precipitation

In this study, Fe2O3/Al2O3catalyst was prepared by using co-precipitation method. This catalyst weight was varied from 0.1 to 0.5 g and multiwalled carbon nanotubes (MWCNTs) bundles were synthesized with ethylene as a carbon precursor at reaction temperature of 800°C by using floating catalytic chemical vapor deposition reactor. The grown MWCNTs bundles were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The obtained data revealed that as prepared CNTs actually existed in bundles and these should be attributed to the Fe2O3/Al2O3catalyst, as transition metal Mo was not used in the catalyst. It was noted that an increase in weight of the catalyst significantly affects the quality, quantity, crystallinity, diameter and the growth of nanotubes bundles. Nanotubes yield increased with an increase in Fe2O3/Al2O3weight. The carbon yield obtained with different weights of Fe2O3/Al2O3was ranging from 68-93%. However, the surface defects in the grown tubes were also increased with an increase in the catalyst weight. High purity and high yield with the low surface defects was found for 0.3 g catalyst. It was found that less value of ID/IGratio (0.78) was obtained in case of 0.3 g catalyst which indicated the structural perfection and low defect levels. The average outer diameter of the grown CNTs bundles were ranged from 240 to 550 nm. The formation of CNTs bundles were found defective with few black spots and impure above and below the use of 0.3 g catalyst.

scholarly journals Synthesis of Co3O4 Nano Aggregates by Co-precipitation Method and its Catalytic and Fuel Additive Applications

2019 ◽  
Vol 17 (1) ◽  
pp. 865-873 ◽  
Author(s):  
Muhammad Ramzan Saeed Ashraf Janjua
Keyword(s):  
Electron Microscopy ◽  
Precipitation Method ◽  
Fuel Additive ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
Calcination Process ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Individual Particles

AbstractThe nano aggregates of cobalt oxide (Co3O4) are synthesized successfully by adopting simple a co precipitation approach. The product obtained was further subjected to the calcination process that not only changed it morphology but also reduces the size of individual particles of aggregates. The prepared nano aggregates are subjected to different characterization techniques such as electron microscopies (scanning electron microscopy and transmission electron microscopy) and X-ray diffraction and results obtained by these instruments are analyzed by different software. The characterization results show that, although the arrangement of particles is compact, several intrinsic spaces and small holes/ pores can also be seen in any aggregate of the product. The as synthesized product is further tested for catalytic properties in thermal decomposition of ammonium perchlorate and proved to be an efficient catalyst.

scholarly journals SERS activity of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. D. Ávila-Avilés ◽  
N. Torres-Gómez ◽  
M. A. Camacho-López ◽  
A. R. Vilchis-Nestor
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Pollen Grains ◽  
Precipitation Method ◽  
Chemical Composition Distribution ◽  
Transmission Electron ◽  
Pollen Surface ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Co Precipitation

Abstract Nature provides remarkable examples of mass-produced microscale particles with structures and chemistries optimized by evolution for particular functions. Synthetic chemical tailoring of such sustainable biogenic particles may be used to generate new multifunctional materials. Herein, we report a facile method for the synthesis of hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template. Silver nanoparticles was biosynthesized using pollen grains as a reduction and stabilization agent as well as a bio-template promoting the adhesion of silver nanoparticles to pollen surface. Fe3O4 nanoparticles were synthesized by co-precipitation method from FeSO4. Hybrid nano/microstructures Ag-Fe3O4 based on Dimorphotheca ecklonis pollen grains as bio-template were obtained and characterized using Scanning Electron Microscopy and Transmission Electron Microscopy to study the morphology and structure; Energy-Dispersive X-ray Spectroscopy to determine the chemical composition distribution; and Confocal Fluorescence Microscopy to demonstrate the fluorescence properties of hybrid nano-microstructures. Furthermore, these hybrid nano-microstructures have been studied by Surface-Enhanced Raman Scattering (SERS), using methylene blue as a target molecule; the hybrid nano-microstructures have shown 14 times signal amplification.

Compound growth and microstructure of carbon nanotube

2003 ◽  
Vol 18 (10) ◽  
pp. 2459-2463 ◽  
Author(s):  
Zaoli Zhang ◽  
Lian Ouyang ◽  
Zujin Shi ◽  
Zhennan Gu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanotube ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multiwalled Carbon ◽  
Catalyst Nanoparticles ◽  
Single Walled Carbon Nanotube ◽  
Fe Catalyst ◽  
Transmission Electron

The compound growth of single-walled carbon nanotube (SWCNT) and multiwalled carbon nanotube (MWCNT), which formed a nanotube cable, was achieved by the chemical vapor deposition of natural gas on an Fe catalyst supported on SiO2–Al2O3 hybrid materials at 950 °C. The microstructure of nanotubes was characterized by high-resolution transmission electron microscopy (HRTEM). The SWCNTs encapsulated inside MWCNTs can be two, three, or even more in quantity with a diameter range from 1.0 nm to 2.0 nm. The diameter of SWCNT is controlled by the size of the catalyst nanoparticles. Some bundles of SWCNT and double-walled nanotubes were also found. The possible mechanism of compound growth is briefly discussed.

scholarly journals Investigation on Variables Contributing to the Synthesis of C-S-H/PCE Nanocomposites by Co-Precipitation Method

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7673
Author(s):  
Ziyang You ◽  
Jing Xu
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Orthogonal Experimental Design ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ultra Fine Particle ◽  
Early Performance ◽  
Co Precipitation

The usage of nanoscale calcium silicate hydrate (nano C-S-H) proved to have an excellent promotion effect on the early performance of concrete as nano C-S-H with ultra-fine particle size can act as seeding for cement hydration. Therefore, it is of importance to tune the particle size during the synthesis process of nano C-S-H. In this paper, the influence of several variables of the particle size distribution (PSD) of nano C-S-H synthesized by chemical co-precipitation method with the aid of polycarboxylate (PCE) was studied by orthogonal experimental design. In addition, the composition, microstructure, and morphology of the C-S-H/PCE nanocomposites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum. The results showed that the concentration of reactants had a significant impact on the PSD of C-S-H/PCE nanocomposites, followed by the dosage of dispersant. Ultrasonic treatment was effective in breaking the C-S-H/PCE aggregates with unstable agglomeration structures. The change in synthetic variables had a negligible effect on the composition of the C-S-H/PCE nanocomposites but had a significant influence on the crystallinity and morphology of the composites.

scholarly journals Electrochemical Performance of Lanthanum Cerium Ferrite Nanoparticles for Supercapacitor Applications

2021 ◽  
Author(s):  
Waseem Raza ◽  
Ghulam Nabi ◽  
Asim Shahzad ◽  
Nafisa Malik ◽  
Nadeem Raza
Keyword(s):  
Electron Microscopy ◽  
Electrode System ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Super Capacitor ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
First Time ◽  
Supercapacitor Applications

Abstract Lanthanum cerium ferrite nanoparticles has been synthesized for the first time via hydrothermal and co-precipitation method. The structural and morphological study of the nanoparticles have been examined by using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDX). The electrochemical study of J1 and J2 electrodes have been examined using three electrode system in 6 M KOH electrolyte using cyclic voltammetry (CV), galvanostatic charging-discharging (GCD) and electrochemical impendence spectroscopy (EIS). The highest specific capacitance of 1195 F/g has been obtained at a scan rate of 10 mV/s from hydrothermal synthesis nanomaterial electrode (J2) and long cycling life 92.3% retention after 2000th cycles. Furthermore, the energy density and power density of the J2 electrode at a current density of 5 A/g was 59 Wh/kg and 9234 W/kg respectively. Hence, the fabricated J2 electrode is a favorable candidate for super-capacitor applications.

Synthesis and Luminescence Properties of Yb3+/Ho3+ Co-Doped Lu2O3 Nanocrystalline Powders

2007 ◽  
Vol 280-283 ◽  
pp. 521-524
Author(s):  
Li Qiong An ◽  
Jian Zhang ◽  
Min Liu ◽  
Sheng Wu Wang
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Co Doped

Yb3+ and Ho3+ co-doped Lu2O3 nanocrystalline powders were synthesized by a reversestrike co-precipitation method. The as-prepared powders were examined by the X-ray diffraction and transmission electron microscopy. The phase composition of the powders was cubic and the particle size was in the range of 30~50 nm. Emission and excitation spectra of the powders were measured by a spectrofluorometer and the possible upconversion luminescence mechanism was also discussed.

scholarly journals Bromate Removal from Water Using Doped Iron Nanoparticles on Multiwalled Carbon Nanotubes (CNTS)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Aasem Zeino ◽  
Abdalla Abulkibash ◽  
Mazen Khaled ◽  
Muataz Atieh
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Iron Nanoparticles ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Transmission Electron

The raw carbon nanotubes (CNTs) were prepared by the floating catalyst chemical vapor deposition method. The raw carbon nanotubes were functionalized, impregnated with iron nanoparticles, and characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The three types of these multiwalled carbon nanotubes were applied as adsorbents for the removal of bromate from drinking water. The effects of the pH, the concentration ofBrO3-anion, the adsorbent dose, the contact time, and the coanions on the adsorption process have been investigated. The results concluded that the highest adsorption capacities were 0.3460 and 0.3220 mg/g through using CNTs-Fe and raw CNTs, respectively, at the same conditions. The results showed that the CNTs-Fe gives higher adsorption capacity compared with the raw CNTs and the functionalized CNTs. The presence of nitrate (NO3-) in the solution decreases the adsorption capacity of all CNTs compared with chloride (Cl-) associated with pH adjustment caused by nitric acid or hydrochloric acid, respectively. However, the adsorption of all MWNCTs types increases as the pH of solution decreases.

Synthesis and Densification of Nanometric Ce0.8Sm0.2O1.9-δ

2006 ◽  
Vol 972 ◽  
Author(s):  
Vincenzo Esposito ◽  
Marco Fronzi ◽  
Enrico Traversa
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Electrochemical Impedance ◽  
Liquid Phase Sintering ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Conventional Sintering ◽  
Eis Measurements ◽  
Co Precipitation

AbstractNanometric 20% molar Sm-doped ceria (SDC20) powders were synthesized by tetrametylethylen ammine (TMDA) co-precipitation method. SDC20 was sintered in several conditions to control the final microstructure. Fast firing and conventional sintering were performed. LiNO3was used as an additive to promote liquid phase sintering of ceria at low temperatures (900-1200°C). Powders and dense pellets were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) measurements were performed on dense pellets in air to estimate the contribution of grain boundary and bulk to the electrical conductivity. Liquid phase sintering produced the densest samples with the highest conductivity.

Study of surface defects and crystallinity of MWCNTs growth in FCCVD

2017 ◽  
Vol 24 (6) ◽  
pp. 845-851
Author(s):  
Shazia Shukrullah ◽  
Norani Muti Mohamed ◽  
Maizatul Shima Shaharun ◽  
Muhammad Yasin Naz
Keyword(s):  
Carbon Nanotubes ◽  
Surface Defects ◽  
Chemical Vapor ◽  
Raman Peak ◽  
Multiwalled Carbon ◽  
Peak Intensity ◽  
Black Spots ◽  
Pure Carbon ◽  
Structural Growth ◽  
Raman Peak Intensity

AbstractThis research investigated the structural growth of multiwalled carbon nanotubes (MWCNTs) in a double stage horizontal chemical vapor deposition (CVD) reactor. Ethylene was used as a carbon source for nucleation of nanotubes. Ferrocene catalyst weight was varied from 0.1 to 0.2 g to demonstrate the growth of MWCNTs on Si/SiO2/Al2O3 substrate. The obtained data revealed that the weight of the catalyst significantly affects the diameter, crystallinity, alignment and yield of the nanotubes. Lower inner-shell spacing and the ratio of D-Raman peak intensity and G-Raman peak intensity (ID/IG ratio) were obtained with 0.15 g of ferrocene, which was an indication of relatively pure carbon nanotubes (CNTs) growth. Raman spectra also confirmed the highly crystalline and relatively pure CNTs structures with ID/IG ratio of 0.700. TGA data revealed the formation of 97% pure nanotubes with oxidation temperature of 620°C. However, above and below the optimum (0.15 g of ferrocene), some of the grown CNTs were found defective and few black spots were also seen in TEM micrographs.

Synthesis of Fe2+ Ion Doped ZnS Nanoparticles

2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Quantum Confinement Effect ◽  
Band Gap Energy ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Co Precipitation

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.

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