Behavior of Ni in carbon nanotube nucleation

Yudasaka, Masako; Kikuchi, Rie; Ohki, Y.; Ota, Etsuro; Yoshimura, Susumu

doi:10.1063/1.118700

Cited by 105 publications

(45 citation statements)

References 4 publications

(3 reference statements)

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“…Large particles and aggregates as compared to fine and well-dispersed particles are inactive for nanotube formation. Optimization of the nano-metal particles and their dispersion in support leads to a maximum number of active points for hydrocarbon decomposition [35][36][37][38][39][40][41][42][43][44]. Accordingly, one of the scientific and technological challenges associated with heterogeneous catalyst system is to find the synthesis methods that fulfill the strong requirements in terms of their composition and structure.…”

Section: Catalystmentioning

confidence: 99%

Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes—A review

Danafar

Fakhru’l‐Razi

Salleh

et al. 2009

Chemical Engineering Journal

170

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a b s t r a c tCarbon nanotubes (CNTs) are pure carbon in nanostructures with unique physico-chemical properties. They have brought significant breakthroughs in different fields such as materials, electronic devices, energy storage, separation, sensors, etc. If the CNTs are ever to fulfill their promise as an engineering material, commercial production will be required. Catalytic chemical vapor deposition (CCVD) technique coupled with a suitable reactor is considered as a scalable and relatively low-cost process enabling to produce high yield CNTs. Recent advances on CCVD of CNTs have shown that fluidized-bed reactors have a great potential for commercial production of this valuable material. However, the dominating process parameters which impact upon the CNT nucleation and growth need to be understood to control product morphology, optimize process productivity and scale up the process. This paper discusses a general overview of the key parameters in the CVD formation of CNT. The focus will be then shifted to the fluidized bed reactors as an alternative for commercial production of CNTs.

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Section: Catalystmentioning

confidence: 99%

Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes—A review

Danafar

Fakhru’l‐Razi

Salleh

et al. 2009

Chemical Engineering Journal

170

View full text Add to dashboard Cite

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“…Recently it has been noticed that the catalyst particle size is an important factor in CNT growth and catalysts with large particle sizes have been claimed ineffective [1][2][3]. Indeed, it has been shown decades ago both experimentally and theoretically that the carbon filament growth rate increases with decreasing catalyst particle size [4,5].…”

Section: Introductionmentioning

confidence: 99%

Effect of catalyst preparation on the carbon nanotube growth rate

Chen

Tøtdal

et al. 2005

Catalysis Today

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“…Following the first reported observation of carbon nanotubes [ 11, numerous papers have reported studies on the yield of carbon nanotubes, their diameter and wall thickness [2-61, growth mechanisms [2,7,8], alignment [6,9], electron emission properties [lo-141, nanodevices [15], theoretical predictions [2], and potential applications [2]. Nanotube alignment is particularly important to enable both fundamental studies and applications, such as flat panel displays, vacuum microelectronics, chargeable batteries, etc.…”

Section: Disclaimermentioning

confidence: 99%

Growth of highly oriented carbon nanotubes by plasma-enhanced hot filament chemical vapor deposition

Huang

Ren

et al. 1998

Applied Physics Letters

271

135

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Highly-oriented, multi-walled carbon nanotubes were grown on polished polycrystalline and single crystal nickel substrates by plasma enhanced hot filament chemical vapor deposition at temperatures below 666°C. The carbon nanotubes range fiom 10 to 500 nm in diameter and 0.1 to 50 pm in length depending on growth conditions. Acetylene is used as the carbon source for the growth of the carbon nanotubes and ammonia is used for dilution gas and catalysis. The plasma intensity, acetylene to ammonia gas ratio and their flow rates, etc. affect the diameters and uniformity of the carbon nanotubes. [2]. Nanotube alignment is particularly important to enable both fundamental studies and applications, such as flat panel displays, vacuum microelectronics, chargeable batteries, etc. However, only one report exists on the growth of aligned carbon nanotubes by thermal decomposition of acetylene in nitrogen gas at temperature above 700°C on mesoporous silica containing iron nanoparticles [6] before our report on growth of large arrays of well-aligned carbon nanotubes on glass [16]. Here we report the growth of highly-oriented, multi-walled carbon nanotubes on nickel substrates at low temperatures by the same method (plasma enhanced hot tungsten-filament chemical vapor deposition) described in our previous paper [16]. The motivation to grow carbon nanotubes on Ni substrates is for the applications of using carbon nanotubes as battery electrodes and energy storage. We use acetylene (C2H2) to provide carbon for the growth of the carbon nanotubes and ammonia (NH3) gas for both dilution gas and catalysis. The catalytic role of ammonia is discussed in our previous paper [ 161.The base pressure of the deposition chamber is < 6 x Torr. We grew carbon nanotube films in a pressure of 1 -20 Torr maintained by flowing acetylene and ammonia gases with a total flow rate of 120 -200 sccm. We varied the acetylene-to-ammonia volume ratio fiom 1 : 2 to 1 : 10 for different experimental runs. Both polished polycrystalline and single-crystal Ni substrates were used. After stabilizing the working pressure, the tungsten filament coil powered by a DC source and the plasma-generator were turned on to generate heat and plasma. Under the present experimental set-up, the temperature of samples is estimated to be below 666 "c (which is the strain point of the display glass provided by Corning Inc.) since the display glass sit side by side with the Ni did not show any noticeable deformation after the experiments [ 161 and also Ni is not red-hot by visual observation. Growth durations were fiom 10 min to 5 h depending on the desired carbon nanotube lengths. Samples were examined by scanning electron microscopy (SEM, Hitachi S-4000) to measure tube lengths, diameters, site distributions, alignment, density and uniformity. High-resolution transmission electron microscopy (TEN was used to determine 2 the microstructure of individual tubes. Samples were also examined by x-ray diffraction, Raman spectroscopy, and x-ray photoemission spectroscopy to stud...

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Behavior of Ni in carbon nanotube nucleation

Cited by 105 publications

References 4 publications

Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes—A review

Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes—A review

Effect of catalyst preparation on the carbon nanotube growth rate

Growth of highly oriented carbon nanotubes by plasma-enhanced hot filament chemical vapor deposition

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