scholarly journals An Investigation on the Formation of Carbon Nanotubes by Two-Stage Chemical Vapor Deposition

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
M. S. Shamsudin ◽  
M. F. Achoi ◽  
M. N. Asiah ◽  
L. N. Ismail ◽  
A. B. Suriani ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Pyrolysis Temperature ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Synthesis Process ◽  
Two Stage ◽  
Synthesis Time ◽  
Custom Made

High density of carbon nanotubes (CNTs) has been synthesized from agricultural hydrocarbon: camphor oil using a one-hour synthesis time and a titanium dioxide sol gel catalyst. The pyrolysis temperature is studied in the range of 700–900°C at increments of 50°C. The synthesis process is done using a custom-made two-stage catalytic chemical vapor deposition apparatus. The CNT characteristics are investigated by field emission scanning electron microscopy and micro-Raman spectroscopy. The experimental results showed that structural properties of CNT are highly dependent on pyrolysis temperature changes.

scholarly journals Catalyst-Less and Transfer-Less Synthesis of Graphene on Si(100) Using Direct Microwave Plasma Enhanced Chemical Vapor Deposition and Protective Enclosures

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5630
Author(s):  
Rimantas Gudaitis ◽  
Algirdas Lazauskas ◽  
Šarūnas Jankauskas ◽  
Šarūnas Meškinis
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Synthesis Process ◽  
Synthesis Time ◽  
Graphene Layers

In this study, graphene was synthesized on the Si(100) substrates via the use of direct microwave plasma-enhanced chemical vapor deposition (PECVD). Protective enclosures were applied to prevent excessive plasma etching of the growing graphene. The properties of synthesized graphene were investigated using Raman scattering spectroscopy and atomic force microscopy. Synthesis time, methane and hydrogen gas flow ratio, temperature, and plasma power effects were considered. The synthesized graphene exhibited n-type self-doping due to the charge transfer from Si(100). The presence of compressive stress was revealed in the synthesized graphene. It was presumed that induction of thermal stress took place during the synthesis process due to the large lattice mismatch between the growing graphene and the substrate. Importantly, it was demonstrated that continuous horizontal graphene layers can be directly grown on the Si(100) substrates if appropriate configuration of the protective enclosure is used in the microwave PECVD process.

scholarly journals Catalytic Chemical Vapor Deposition of Methane to Carbon Nanotubes: Copper Promoted Effect of Ni/MgO Catalysts

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Wen Yang ◽  
Yanyan Feng ◽  
Wei Chu
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Calcination Temperature ◽  
Reaction Temperature ◽  
Vapor Deposition ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Growth And Yield ◽  
Calcination Temperatures ◽  
Temperature Programmed

The Ni/MgO and Ni-Cu/MgO catalysts were prepared by sol-gel method and used as the catalysts for synthesis of carbon nanotubes by thermal chemical vapor deposition. The effect of Cu on the carbon yield and structure was investigated, and the effects of calcination temperature and reaction temperature were also investigated. The catalysts and synthesized carbon materials were characterized by temperature programmed reduction (TPR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Results showed that the addition of Cu promoted the reduction of nickel species, subsequently improving the growth and yield of CNTs. Meanwhile, CNTs were synthesized by the Ni/MgO and Ni-Cu/MgO catalysts with various calcination temperatures and reaction temperatures, and results suggested that the obtained CNTs on Ni-Cu/MgO catalyst with the calcination temperature of 500°C and the reaction temperature of 650°C were of the greatest yield and quantity of 927%.

Synthesis of Carbon Nanotubes and its Applications in Composites and Field Emission Light

2007 ◽  
Vol 539-543 ◽  
pp. 3491-3496
Author(s):  
Nyan Hwa Tai ◽  
Meng Kao Yeh ◽  
Chien Hsin Yang ◽  
Shis Hao Tseng ◽  
Chien Chao Chiu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Electron Microscope ◽  
Field Emission ◽  
Vapor Deposition ◽  
Rapid Heating ◽  
High Current Density ◽  
Chemical Vapor ◽  
Synthesis Process ◽  
Walled Carbon Nanotubes

Two processes, the floating catalyst chemical vapor deposition (CVD) process and the rapid heating and cooling (RHC) process, were adopted for synthesizing single walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). Batch production of SWNTs and MWNTs with the diameters of 0.8~1.5 nm and 15~40 nm, respectively, were prepared using the floating catalytic chemical vapor deposition (CCVD) process. The production rate is 70±20 mg every 10 minutes. The as-synthesized carbon nanotubes (CNTs) were used for fabricating carbon nanotubes reinforced composites and field emitter for lighting. On the study of nano-composites, around 70% enhancement of tensile strength was detected when 1.5 wt% MWNTs in the form of network structure were introduced to the phenolic matrix. Comparisons on the mechanical properties of the composites reinforced with the network MWNTs and SWNTs were made. Microstructures of the MWNTs and SWNTs were studied by Field Emission Scanning Electron Microscope (FESEM) and High Resolution Transmission Electron Microscope (HRTEM). In the RHC process for fabricating the device for lighting, the carbon nanotube array was grown on a silicon substrate which was pre-coated with a catalyst thin film. The synthesis process was performed in a thermal CVD chamber equipped with a rapid heating apparatus. The as-synthesized CNT array was then transferred onto the substrate which was coated with silver paste. After heat treatment, field emission properties of the CNT-based cathode were tested, high current density of 35 mA/cm2 and low turn-on voltage of 0.65 V/μm were achieved in this work.

Structural and Thermal Behaviors of Iron-Filled Align Carbon Nanotubes Formulated by Two-Stage Catalytic Chemical Vapor Deposition

2011 ◽  
Vol 364 ◽  
pp. 191-195 ◽  
Author(s):  
Muhammad Salleh Shamsudin ◽  
Saifollah Abdullah ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Free Standing ◽  
Two Stage ◽  
Catalytic Chemical Vapor Deposition ◽  
Chemical Technique ◽  
Align Carbon Nanotubes ◽  
Wet Chemical Technique

Finding on the one-dimensional purified aligned carbon nanotubes (ACNT) was prepared using botanical hydrocarbon: camphor powder in a two-stage catalytic chemical vapor deposition will be presented. For the first time, the hydrocarbon source and catalyst were patterned in different alumina boats in the system. The growth of ACNT has achieved free standing formation with higher aspect ratio. In contrast, unpurified carbon nanotubes have some drawbacks and require some treatments to fully utilize their capabilities in various applications. The results reveal that the crystallinity and purity of functionalized align carbon nanotubes was increased after wet-chemical technique and heat treatment process. In this paper, the results provide evidence showing that it was in good agreement with the field emission scanning electron microscopy, micro-Raman and thermogravimetric analysis.

Cobalt supported on carbon nanotubes for methane chemical vapor deposition towards carbon nanotubes

2021 ◽  
Author(s):  
Laura Esteves ◽  
Hugo Alvarenga Oliveira ◽  
Y. T. Xing ◽  
Fabio Barboza Passos
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Heterogeneous Catalysis ◽  
Vapor Deposition ◽  
Supported Catalysts ◽  
Chemical Vapor

Carbon nanotubes (CNT) application in heterogeneous catalysis has been attracting growing interest. However, the use of CNT-supported catalysts in the chemical vapor deposition for the production of new CNT is...

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