Fine-tuning control on CNT diameter distribution, length and density using thermal CVD growth at atmospheric pressure: an in-depth analysis on the role of flow rate and flow duration of acetylene (C2H2) gas

Tripathi, Nishant; Mishra, Prabhash; Harsh, Harsh

doi:10.1007/s13204-013-0288-8

Cited by 39 publications

(10 citation statements)

References 24 publications

(19 reference statements)

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“…If the flow rate of acetylene gas is high, the diffusion of large amounts of carbon atoms towards the catalyst particle was high that tends to increase the dispersion rate. At high diffusion rate of carbon, the large amount carbon present in catalyst particle starts to reduce the activity of the catalyst, due to catalyst particles being covered by amorphous carbon, that increase the thickness of the MWCNTs [33] and it is clearly evident in Fig. 4e.…”

Section: Effect Of the Flow Rate Of The Precursor Gasmentioning

confidence: 97%

Effect of chemical vapor deposition parameters on the diameter of multi-walled carbon nanotubes

et al. 2018

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The multi-walled carbon nanotubes (MWCNTs) with controlled diameter distribution are useful in the fabrication of composite materials as reinforcement, due to their superior strength and toughness. Chemical vapor deposition (CVD) is a viable process to synthesize MWCNTs. In this investigation, an attempt has been made to study the effect of CVD process parameters (reaction temperature, flow rate of precursor gas, process time) on the mean diameter of MWCNTs. The MWCNTs of controlled diameter distribution was selectively grown on NiO catalyst supported by Al 2 O 3 nano particles. The argon and acetylene were used as carrier and carbon precursor gas, respectively. The catalyst and carbon samples were characterized using field emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy and thermogravimetric/differential thermal analysis. From this investigation, it is understood that the increase in reaction temperature and flow rate of precursor gas increased the mean diameter of MWCNTs but increase in process time decreased the diameter. The diameter distribution and quality of MWCNTs are strongly influenced by the diameter of the catalyst particles.

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Section: Effect Of the Flow Rate Of The Precursor Gasmentioning

confidence: 97%

Effect of chemical vapor deposition parameters on the diameter of multi-walled carbon nanotubes

et al. 2018

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“…initial growth rate and the characteristic catalyst lifetime 10 . Since then only a few papers were published which attempted to find correlation between gas feed (mostly acetylene as carbon source, argon as carrier and hydrogen as reducing agent) and the characteristics of vertically aligned carbon nanotubes 11 – 14 .…”

Section: Introductionmentioning

confidence: 99%

Influence of synthesis parameters on CCVD growth of vertically aligned carbon nanotubes over aluminum substrate

Szabó

Kecsenovity

Pápa

et al. 2017

Sci Rep

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In the past two decades, important results have been achieved in the field of carbon nanotube (CNT) research, which revealed that carbon nanotubes have extremely good electrical and mechanical properties The range of applications widens more, if CNTs form a forest-like, vertically aligned structure (VACNT) Although, VACNT-conductive substrate structure could be very advantageous for various applications, to produce proper system without barrier films i.e. with good electrical contact is still a challenge. The aim of the current work is to develop a cheap and easy method for growing carbon nanotubes forests on conductive substrate with the CCVD (Catalytic Chemical Vapor Deposition) technique at 640 °C. The applied catalyst contained Fe and Co and was deposited via dip coating onto an aluminum substrate. In order to control the height of CNT forest several parameters were varied during the both catalyst layer fabrication (e.g. ink concentration, ink composition, dipping speed) and the CCVD synthesis (e.g. gas feeds, reaction time). As-prepared CNT forests were investigated with various methods such as scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry. With such an easy process it was possible to tune both the height and the quality of carbon nanotube forests.

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“…However, the overly high C 2 H 2 flow rate meant an excess carbon supply, which led to the increase in amorphous carbonaceous products and other impurities on the catalyst particles as well as on the surface of grown CNTs. Furthermore, the catalyst particles were poisoned by the amorphous carbon and, thus, formed short and thick CNTs [ 38 , 39 ].…”

Section: Resultsmentioning

confidence: 99%

In Situ Synthesis of Carbon Nanotube–Steel Slag Composite for Pb(II) and Cu(II) Removal from Aqueous Solution

Yang

Wang

et al. 2022

Nanomaterials

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Methods and materials that effectively remove heavy metals, such as lead and copper, from wastewater are urgently needed. In this study, steel slag, a low-cost byproduct of steel manufacturing, was utilized as a substrate material for carbon nanotube (CNT) growth by chemical vapor deposition (CVD) to produce a new kind of efficient and low-cost absorbent without any pretreatment. The synthesis parameters of the developed CNT–steel slag composite (SS@CNTs) were optimized, and its adsorption capacities for Pb(II) and Cu(II) were evaluated. The results showed that the optimal growth time, synthesis temperature and acetylene flow rate were 45 min, 600 °C and 200 sccm (standard cubic centimeter per minute), respectively. The SS@CNTs composite had a high adsorption capacity with a maximum removal amount of 427.26 mg·g−1 for Pb(II) and 132.79 mg·g−1 for Cu(II). The adsorption proceeded rapidly during the first 15 min of adsorption and reached equilibrium at approximately 90 min. The adsorption processes were in accordance with the isotherms of the Langmuir model and the pseudo-second-order model, while the adsorption thermodynamics results indicated that the removal for both metals was an endothermic and spontaneous process. This study showed that compared with other adsorbent materials, the SS@CNTs composite is an efficient and low-cost adsorbent for heavy metals such as lead and copper.

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Fine-tuning control on CNT diameter distribution, length and density using thermal CVD growth at atmospheric pressure: an in-depth analysis on the role of flow rate and flow duration of acetylene (C2H2) gas

Cited by 39 publications

References 24 publications

Effect of chemical vapor deposition parameters on the diameter of multi-walled carbon nanotubes

Effect of chemical vapor deposition parameters on the diameter of multi-walled carbon nanotubes

Influence of synthesis parameters on CCVD growth of vertically aligned carbon nanotubes over aluminum substrate

In Situ Synthesis of Carbon Nanotube–Steel Slag Composite for Pb(II) and Cu(II) Removal from Aqueous Solution

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