Effects of synthesis conditions on the synthesis of carbon nanofibers by ethanol catalytic combustion

2012 ◽  
Vol 57 (3) ◽  
pp. 745-751
Author(s):  
J. Cheng ◽  
X.P. Zou ◽  
G. Zhu ◽  
M. F. Wang ◽  
Y. Su ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Nickel Chloride ◽  
Cobalt Nitrate ◽  
Iron Chloride ◽  
Single Type ◽  
Preparation Time ◽  
Optimal Position ◽  
Synthesis Conditions

In this paper, the effects of position of substrates in flames, preparation time, stability of flames and catalyst precursors on the synthesis of carbon nanofibers (CNFs) by ethanol catalytic combustion (ECC) were investigated. For investigating the effects of these influence factors on the synthesis of CNFs, several sets of controlled experiments were performed, such as preparation experiments with different position of substrates in flames, different preparation time, stable and unstable flames, and different catalyst precursors. In our experiments, the catalyst precursors were iron nitrate, cobalt nitrate, nickel nitrate, and iron chloride, cobalt chloride, nickel chloride. The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Our results indicate that the optimal position of substrates in flames is more than 1cm and less than 2.5cm, the optimal preparation time is more than 5min and less than 30min for massive yield, stable flames would be tent to synthesize CNFs with mainly single-type morphology and could improve the graphitization of CNFs, and the catalyst precursors obviously have effects on the synthesis of CNFs.

Effects of Synthesis Parameters on the Preparation of Carbon Nanofibers by Ethanol Catalytic Combustion

2011 ◽  
Vol 264-265 ◽  
pp. 843-848
Author(s):  
Jin Cheng ◽  
Xiao Ping Zou
Keyword(s):  
Carbon Source ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Experimental Results ◽  
Preparation Time ◽  
Optimal Position ◽  
Synthesis Parameters ◽  
Good Uniformity ◽  
Lower Height ◽  
The Stability

In this paper, the effects of position of substrates in flames, preparation time and stability of flames on carbon nanofibers are investigated in ethanol catalytic combustion. For the position of substrates, our results indicate that the temperature at the lower height (h<1cm) is too low (less that 500°C) to grow carbon nanofibers; the temperature at higher height (h>2.5cm) is suitable for the growth of carbon nanofibers, but the carbon source is insufficient because of sufficient combustion of ethanol; the optimal position of substrates in flames is more than 1cm and less than 2.5cm for massive yield because the temperature of flames is suitable for the growth of carbon nanofibers and the carbon source is also sufficient. For the preparation time, our results indicate that the optimal preparation time is more than 5min and less than 30min for massive yield. If the preparation time is excessive long (more that 30min), the deposits partly become burning in flames due to excessive products on substrates. The stability of flames has effects on the morphology and graphitization of products. Our experimental results indicate that stable flames prefer to produce noncoiled carbon nanofibers with relatively good uniformity and higher graphitization because the relatively stable flames could provide a relative stable synthesis environment.

Catalytic Combustion Synthesis of Carbon Nanofibers

2007 ◽  
Vol 561-565 ◽  
pp. 1537-1540
Author(s):  
Guang Zhu ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Fei Li ◽  
Hong Dan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Influence Factors ◽  
Simple Method ◽  
Environment Friendly ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Combustion Technique

The catalytic combustion technique was used to synthesize carbon nanotubes and carbon nanofibers. In this paper, we report that carbon nanofibers were synthesized by ethanol catalytic combustion technique. The as-grown products were characterized by means of scanning electron microscopy, transmission electron microscopy, Raman spectroscopy. The results showed that the products have a mass of carbon nanofibers. However, morphology and microstructure of carbon nanofibers are affected by synthesis conditions, such as stability of flames and sampling time, sampling temperature etc. Different Influence factors were depicted in detail. Ethanol catalytic combustion technique offer a simple method to synthesize carbon nanotubes and carbon nanofibers, it also has some advantages, such as flexible synthesis conditions, simple setup, and environment-friendly.

The Influence of Catalyst Nature on the Morphology of Multi-Directionally Grown Carbon Nanofibers

2007 ◽  
Vol 26-28 ◽  
pp. 735-738
Author(s):  
Fei Li ◽  
Xiao Ping Zou ◽  
Jin Cheng
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Close Relation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Combustion Technique

The multi-directional grown carbon nanofibers have been synthesized by catalytic combustion technique. Transmission electron microscopy and selected area electron X-ray diffraction were combined to characterize the carbon products and their catalyst, which promoted the formation of carbon nanofibers. The crystal structures of the catalyst were investigated. The present results indicate that the morphologies of the carbon nanofibers have a close relation with the crystal structure of the catalysts.

Synthesis of Carbon Nanofibers by Ethanol Catalytic Combustion Technique

2007 ◽  
Vol 26-28 ◽  
pp. 731-734
Author(s):  
Peng Fei Ren ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Hong Dan Zhang ◽  
Fei Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Nanofibers ◽  
Helical Structure ◽  
Copper Plate ◽  
Iron Chloride ◽  
Catalyst Precursor ◽  
Iron Nitrate ◽  
Transmission Electron ◽  
Simple Growth

In this paper, we report a simple growth of carbon nanofibers by means of the combustion of ethyl alcohol. In our experiment, copper plate was employed as substrate, iron nitrate and iron chloride as catalyst precursor and ethanol as carbon source. The as-grown carbon nanofibers were characterized by employing scanning electron microscopy, transmission electron microscopy, high-resolution field-emission transmission electron microscopy and Reinshaw optical confocal Raman spectroscopy. Our results suggested that it would tend to form relatively uniform nanofibers when the catalyst precursor was iron nitrate, however, to form some helical structure nanofibers when the catalyst precursor was iron chloride. The sample using iron chloride as the catalyst precursor has a higher graphitization degree than that using iron nitrate as the catalyst precursor.

Influence of Carbon Sources and Catalytic Precursors on the Products Prepared by Catalytic Combustion

2008 ◽  
Vol 47-50 ◽  
pp. 912-915
Author(s):  
Mao Fa Wang ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Guang Zhu ◽  
Yi Su
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Carbon Sources ◽  
Combustion Process ◽  
Deep Understanding ◽  
Precursor Solution ◽  
Controlled Synthesis ◽  
Catalyst Precursor ◽  
Scanning Electron

It is very important to study the effects of various factors on synthesis of carbon nanofibers for controlled synthesis, which plays a significant role in realizing desired nanostructures or nanodevices for applications. In this report, we employed different carbon source and different catalyst precursor solution, respectively, and studied the effects of those on carbon nanofibers that were synthesized by catalytic combustion process. We have characterized the as-grown carbon nanofibers by employing scanning electron microscopy (SEM) for deep understanding.

scholarly journals Improving stability of cerium oxide nanoparticles by microbial polysaccharides coating

2018 ◽  
Vol 83 (6) ◽  
pp. 745-757 ◽  
Author(s):  
Ivana Milenkovic ◽  
Ksenija Radotic ◽  
Branko Matovic ◽  
Marija Prekajski ◽  
Ljiljana Zivkovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cerium Oxide ◽  
Aqueous Media ◽  
Suspension Stability ◽  
X Ray Diffraction ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Ft Ir ◽  
Microbial Exopolysaccharides ◽  
The Stability

Cerium oxide (CeO2) nanoparticles (CONPs) are interesting biomaterials with various applications in biomedicine, cosmetics and the pharmaceutical industry, but with limited practical application because of their low stability in aqueous media. The aim of this study was to obtain CONPs with increased stability by coating the particles. Microbial exopolysaccharides (levan, pullulan) and glucose were used to prepare CONPs under different synthesis conditions. Coating was attempted by adding the carbohydrates during (direct coating) or after (subsequent coating) the synthesis of CONPs. The obtained nanoparticles were characterized by X-Ray diffraction analysis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The suspension stability of the uncoated and coated CONPs in aqueous media was evaluated by measuring the hydrodynamic size, zeta potential and turbidity. The FT-IR spectra revealed the differences between coated CONPs and showed the success of subsequent coating with carbohydrates. Coating with carbohydrates improved the stability the CONP suspension by decreasing the size of aggregated particles. The suspensions of levan- and glucose-coated CONPs had the best stability. In this study, CONPs were prepared using non-toxic materials, which were completely environmentally friendly. The obtained results open new horizons for CONP synthesis, improving their biological applications.

scholarly journals K-paracelsian (KAlSi3O8·H2O) and identification of a simple building scheme of dense double-crankshaft zeolite topologies

IUCrJ ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Cristian-R. Boruntea ◽  
Peter N. R. Vennestrøm ◽  
Lars F. Lundegaard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Space ◽  
Ex Situ ◽  
Zeolite Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Small Pore ◽  
Scanning Electron

During screening of the phase space using KOH and 1-methyl-4-aza-1-azoniabicyclo[2.2.2]octane hydroxide (1-methyl-DABCO) under hydrothermal zeolite synthesis conditions, K-paracelsian was synthesized. Scanning electron microscopy, energy dispersive X-ray spectroscopy and ex situ powder X-ray diffraction analysis revealed a material that is compositionally closely related to the mineral microcline and structurally closely related to the mineral paracelsian, both of which are feldspars. In contrast to the feldspars, K-paracelsian contains intrazeolitic water corresponding to one molecule per cage. In the case of K-paracelsian it might be useful to consider it a link between feldspars and zeolites. It was also shown that K-paracelsian can be described as the simplest endmember of a family of dense double-crankshaft zeolite topologies. By applying the identified building principle, a number of known zeolite topologies can be constructed. Furthermore, it facilitates the construction of a range of hypothetical small-pore structures that are crystallo-chemically healthy, but which have not yet been realized experimentally.

scholarly journals Carbon Nanofibers from Carbon Nanotubes by 1.2 keVAr+Sputtering at Room Temperature

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shuang-Xi Xue ◽  
Qin-Tao Li ◽  
Xian-Rui Zhao ◽  
Qin-Yi Shi ◽  
Zhi-Gang Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanofibers ◽  
Carbon Nanoparticles ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanowires

Multi-walled carbon nanotubes (MWCNTs) were irradiated by 1.2 keV Ar ion beams for 15–60 min at room temperature with current density of 60 µA/cm2. The morphology and microstructure are investigated by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that carbon nanofibers are achieved after 60 min ion irradiation and the formation of carbon nanofibers proceeds through four periods, carbon nanotubes—amorphous carbon nanowires—carbon nanoparticles along the tube axis—conical protrusions on the nanoparticles surface—carbon nanofibers from the conical protrusions.

Synthesis of Carbon Nanofibers by Ethanol Catalytic Combustion Technique

2007 ◽  
pp. 731-734
Author(s):  
Peng Fei Ren ◽  
Xiao Ping Zou ◽  
Jin Cheng ◽  
Hong Dan Zhang ◽  
Fei Li ◽  
...  
Keyword(s):  
Carbon Nanofibers ◽  
Catalytic Combustion ◽  
Combustion Technique

scholarly journals Co3O4Electrode Prepared by Using Metal-Organic Framework as a Host for Supercapacitors

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jiaqiang Jiang ◽  
Fuxiang Wei ◽  
Genxi Yu ◽  
Yanwei Sui
Keyword(s):  
Electron Microscopy ◽  
Specific Capacitance ◽  
Metal Organic Framework ◽  
High Specific Capacitance ◽  
Cobalt Nitrate ◽  
High Rate ◽  
Phase Method ◽  
Simple Liquid ◽  
Metal Organic ◽  
Organic Framework

Co3O4nanoparticles were prepared from cobalt nitrate that was accommodated in the pores of a metal-organic framework (MOF) ZIF-8 (Zn(MeIM)2, MeIM = 2-methylimidazole) by using a simple liquid-phase method. Analysis by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the obtained Co3O4was composed of separate nanoparticles with a mean size of 30 nm. The obtained Co3O4nanoparticles exhibited superior electrochemical property. Co3O4electrode exhibited a maximum specific capacitance of 189.1 F g−1at the specific current of 0.2 A g−1. Meanwhile, the Co3O4electrode possessed the high specific capacitance retention ratio at the current density ranging from 0.2 to 1.0 A g−1, thereby indicating that Co3O4electrode suited high-rate charge/discharge.

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