Low temperature growth of carbon nanotubes on tetrahedral amorphous carbon using Fe–Cu catalyst

Cartwright, Richard; Esconjauregui, Santiago; Hardeman, David; Bhardwaj, Sunil; Weatherup, Robert S.; Guo, Yuzheng; D’Arsié, Lorenzo; Bayer, Bernhard C.; Kidambi, Piran R.; Hofmann, Stephan; Wright, Edward; Clarke, J. T.; Oakes, D.; Cepek, Cinzia; Robertson, John

doi:10.1016/j.carbon.2014.10.001

Cited by 31 publications

(26 citation statements)

References 49 publications

(62 reference statements)

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“…In [11] it is stated that the ta-C layer remains unaffected by the synthesis of the MWCNTs carried out in similar temperature range as our process. It should however be noted that the ta-C layer thickness used in [11] is much larger than here (100 nm vs. 15 nm) so it may be that with such thick layers the ta-C remains unaffected by the growth process to a large extent. In addition, there is a thick SiO 2 layer on top of the Si in [11] whereas in our case we have only the native oxide on top of our Si substrate.…”

Section: Changes In the Ta-c Film During Processingmentioning

confidence: 54%

“…It should however be noted that the ta-C layer thickness used in [11] is much larger than here (100 nm vs. 15 nm) so it may be that with such thick layers the ta-C remains unaffected by the growth process to a large extent. In addition, there is a thick SiO 2 layer on top of the Si in [11] whereas in our case we have only the native oxide on top of our Si substrate. This will affect the diffusion behavior of the species in the system and may reduce the possibility of nanoparticle induced graphitization of the ta-C layer.…”

Section: Changes In the Ta-c Film During Processingmentioning

confidence: 87%

“…In another very recent study, MWCNTs were grown on top of ta-C surfaces by utilizing Fe-Cu bimetallic catalyst at around 500°C [11]. This in depth investigation reports the effect of various different growth parameters on the resulting structures.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Multi-walled carbon nanotubes (MWCNTs) grown directly on tetrahedral amorphous carbon (ta-C): An interfacial study

Laurila

Sainio

Jiang

et al. 2015

Diamond and Related Materials

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Section: Changes In the Ta-c Film During Processingmentioning

confidence: 54%

Section: Changes In the Ta-c Film During Processingmentioning

confidence: 87%

See 1 more Smart Citation

Multi-walled carbon nanotubes (MWCNTs) grown directly on tetrahedral amorphous carbon (ta-C): An interfacial study

Laurila

Sainio

Jiang

et al. 2015

Diamond and Related Materials

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“…The enhanced catalytic activity of Fe-Cu catalysts has been attributed to the special role played by Cu as a promoter, by enhancing the stability and reducing the reduction temperature of Fe. 8,42,43 The striking difference in the activity of Fe-Cu and Fe catalysts in our work, especially at temperatures higher than 450°C, suggests that the synergistic effect between Fe and Cu is temperature dependent as it appears to be highly favorable beyond 450°C. We therefore conclude that the CNT carpet growth efficiency observed at 400 and 450°C, temperatures where the role of Cu appear to be weak, is largely due to the unique properties of FTS-GP.…”

Section: Resultsmentioning

confidence: 76%

Gaseous product mixture from Fischer–Tropsch synthesis as an efficient carbon feedstock for low temperature CVD growth of carbon nanotube carpets

et al. 2016

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Low-temperature chemical vapor deposition (CVD) growth of carbon nanotube (CNT) carpets from Fe and Fe-Cu catalysts using a gaseous product mixture from Fischer-Tropsch synthesis (FTS-GP) as a superior carbon feedstock is demonstrated. This growth approach addresses a persistent issue of obtaining thick CNT carpets on temperature-sensitive substrates at low temperatures using a non-plasma CVD approach without catalyst pretreatment and/or preheating of the carbon feedstock. The efficiency of the process is evidenced by the highly dense, vertically aligned CNT structures from both Fe and Fe-Cu catalysts even at temperatures as low as 400 °C - a record low growth temperature for CNT carpets obtained via conventional thermal CVD. The grown CNTs exhibit a straight morphology with hollow interior and parallel graphitic planes along the tube walls. The apparent activation energies for CNT carpet growth on Fe and Fe-Cu catalysts are 0.71 and 0.54 eV, respectively. The synergistic effect of Fe and Cu show a strong dependence on the growth temperature, with Cu being more influential at temperatures higher than 450 °C. The low activation energies and long catalyst lifetimes observed are rationalized based on the unique composition of FTS-GP and Gibbs free energies for the decomposition reactions of the hydrocarbon components. The use of FTS-GP facilitates low-temperature growth of CNT carpets on traditional (alumina film) and nontraditional substrates (aluminum foil) and has the potential of enhancing CNT quality, catalyst lifetime, and scalability.

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“…A porous Ni-Cu-Co alloy catalyst was studied by Lua and Wang [25] for the decomposition of methane for hydrogen and carbon nanotubes production. The interaction between Cu and Fe was found to enhance the nucleation of nanotubes over Fe as well as minimize the bulk accumulation of carbon substrates [26]. In terms of hydrogen production, Wu and Williams [27,28] have suggested that a bimetallic Ni-Mg catalyst presented higher catalytic activity towards hydrogen production than a monometallic Ni catalyst.…”

Section: Introductionmentioning

confidence: 99%

Co-production of hydrogen and carbon nanotubes from real-world waste plastics: Influence of catalyst composition and operational parameters

Yao

Zhang

Williams

et al. 2018

Applied Catalysis B: Environmental

238

134

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A B S T R A C TThe use of Ni-Fe catalysts for the catalytic pyrolysis of real-world waste plastics to produce hydrogen and high value carbon nanotubes (CNT), and the influence of catalyst composition and support materials has been investigated. Experiments were conducted in a two stage fixed bed reactor, where plastics were pyrolysed in the first stage followed by reaction of the evolved volatiles over the catalyst in the second stage. Different catalyst temperatures (700, 800, 900°C) and steam to plastic ratios (0, 0.3, 1, 2.6) were explored to optimize the product hydrogen and the yield of carbon nanotubes deposited on the catalyst. The results showed that the growth of carbon nanotubes and hydrogen were highly dependent on the catalyst type and the operational parameters. Fe/ γ-Al 2 O 3 produced the highest hydrogen yield (22.9 mmol H 2 /g plastic ) and carbon nanotubes yield (195 mg g −1 plastic ) among the monometallic catalysts, followed by Fe/α-Al 2 O 3 , Ni/γ-Al 2 O 3 and Ni/α-Al 2 O 3 . The bimetallic Ni-Fe catalyst showed higher catalytic activity in relation to H 2 yield than the monometallic Ni or Fe catalysts because of the optimum interaction between metal and support. Further investigation of the influence of steam input and catalyst temperature on product yields found that the optimum simultaneous production of CNTs (287 mg g −1 plastic ) and hydrogen production (31.8 mmol H 2 /g plastic ) were obtained at 800°C in the absence of steam and in the presence of the bimetallic Ni-Fe/γ-Al 2 O 3 catalyst.

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Low temperature growth of carbon nanotubes on tetrahedral amorphous carbon using Fe–Cu catalyst

Cited by 31 publications

References 49 publications

Multi-walled carbon nanotubes (MWCNTs) grown directly on tetrahedral amorphous carbon (ta-C): An interfacial study

Multi-walled carbon nanotubes (MWCNTs) grown directly on tetrahedral amorphous carbon (ta-C): An interfacial study

Gaseous product mixture from Fischer–Tropsch synthesis as an efficient carbon feedstock for low temperature CVD growth of carbon nanotube carpets

Co-production of hydrogen and carbon nanotubes from real-world waste plastics: Influence of catalyst composition and operational parameters

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