Temperature effect on the growth of carbon nanotubes using thermal chemical vapor deposition

Lee, Cheol Jin; Park, Jeunghee; Huh, Yong-Hak; Lee, Jun Young

doi:10.1016/s0009-2614(01)00680-7

Cited by 260 publications

(130 citation statements)

References 23 publications

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“…In our experience we have also found that temperatures below 850°C are too low to effectively synthesize CNTs using CH 4 on thin film catalysts. Similar works have reported that higher growth temperature yields more effective synthesis with CH 4 [36,37]. We performed several experiments with the ratio of H 2 to CH 4 of 50:100, 40:100, 34:100, and 24:100 at a temperature range of 925-1000°C.…”

Section: Resultsmentioning

confidence: 75%

Carbon nanotube diameter tuning using hydrogen amount and temperature on SiO2/Si substrates

Aksak

Selamet

2010

Appl. Phys. A

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Carbon nanotubes (CNTs) were grown on thin iron (Fe) films on SiO 2 /Si substrates by chemical vapor deposition (CVD) at four different hydrogen (H 2 )/methane (CH 4 ) ratios at temperatures ranging from 925 to 1000°C. The effects of temperature and the amount of hydrogen gas on the mean diameter at increasing temperature were examined. We demonstrated that the mean diameter and its distribution depend not only on temperature but also on the H 2 amount. We showed that increasing H 2 amount strongly affects the structure of CNTs, especially at high growth temperature; the mean diameter at 1000°C reduced from about 383 to 34 nm by increasing H 2 amount from 24 to 50 sccm. We observed that at high temperature growth the mean diameter was decreasing very fast initially with increasing H 2 amount suggesting the dominance of H 2 over the growth temperature. A decrease in the slope of diameter vs. H 2 amount with further increment in H 2 amount implied that the temperature was, then, deciding the CNT diameter through catalyst particle coarsening. The statistical analysis presented implies that the H 2 amount has to be adjusted according to the growth temperature for given CH 4 amount to keep CNT diameter under control, and the large diameter distributions at high temperature and high H 2 amount can be associated with the large variation in the catalyst particle sizes.M. Aksak · Y. Selamet ( ) Carbon

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Section: Resultsmentioning

confidence: 75%

Carbon nanotube diameter tuning using hydrogen amount and temperature on SiO2/Si substrates

Aksak

Selamet

2010

Appl. Phys. A

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“…A huge increase in catalytic activity is shown in Figure 7A, where the total amount of carbon uptake went from 5.4% to nearly 60%. This trend has been evidenced [32,33] where the temperature has a direct effect on the CVD deposition amount, due to an overcoming of the methane dissociation energy barrier. Despite the higher activity, the G/D area ratio decreases strongly, and the amount of SWCNT formed also diminishes with temperature ( Figure 7B), leading to a complete loss of activity to SWCNTs.…”

Section: Effect Of Reaction Temperature On Cvd Processmentioning

confidence: 87%

Single Wall Carbon Nanotubes Synthesis through Methane Chemical Vapor Deposition over MCM-41–Co Catalysts: Variables Optimization

Rodriguez

López

Giraldo

2018

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MCM-41-Co catalysts were tested in the synthesis of single wall carbon nanotubes (SWCNTs) through methane chemical vapor deposition (CVD), varying total cobalt content, synthesis temperature, methane flow rate, and deposition time. All variables showed a relationship with total carbon deposition, graphitic quality according to Raman results. Cobalt content showed a maximum activity at 4%, but the structural quality is best at 3%. Flow rate does not affect the quality up to 300 cm 3 min −1 , but deposition time leads to the formation of highly disordered carbon species passing methane for periods longer than 30 min, concluding that optimal variables are a methane deposition temperature of 800 • C, a 300 cm 3 min −1 methane flow rate, and a 30 min of methane injection time, leading to a 5.4% carbon mass content and 5.1 G/D area ratios.

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“…For the normal CNTs, it is generally accepted that the catalytic growth process consists mainly of three steps: small carbon species adsorb, dissolve, and diffuse in catalyst particles, then graphene layers nucleate on the surfaces of the catalyst particle, and finally grow into tubular structures [19], [20] and [21]. This mechanism can well explain the growth process of the normal tubes formed in the detonation approach [15].…”

Section: The Growth Of Bamboo-shape Cntsmentioning

confidence: 95%

Formation of bamboo-shape carbon nanotubes by controlled rapid decomposition of picric acid

Lu¹,

Zhu²,

Su³

et al. 2004

Carbon

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In the presence of catalysts, carbon nanotubes (CNTs) can efficiently grow in the environment generated by the rapid decomposition of normal explosives. Controlling the reaction parameters of a mixture of picric acid (PA) with cobalt acetate and paraffin can lead to a welldefined morphology of CNTs. The formation of bamboo-shape tubes is favorable at relatively high Co(AC) 2 /PA and paraffin/PA ratios. It is found that the bamboo-shape tubes are different in morphology and structure and can be categorized roughly into two types, according to the participation of the catalyst nanoparticles. The formation of the two types is discussed.

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Temperature effect on the growth of carbon nanotubes using thermal chemical vapor deposition

Cited by 260 publications

References 23 publications

Carbon nanotube diameter tuning using hydrogen amount and temperature on SiO2/Si substrates

Carbon nanotube diameter tuning using hydrogen amount and temperature on SiO2/Si substrates

Single Wall Carbon Nanotubes Synthesis through Methane Chemical Vapor Deposition over MCM-41–Co Catalysts: Variables Optimization

Formation of bamboo-shape carbon nanotubes by controlled rapid decomposition of picric acid

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