Influence of ethanol in the presence of H2 on the catalytic growth of vertically aligned carbon nanotubes

Guellati, O.; Janowska, Izabela; Bégin, Dominique; Guérioune, M.; Mekhalif, Zineb; Delhalle, Joseph; Moldovan, Simona; Ersen, Ovidiu; Pham‐Huu, Cuong

doi:10.1016/j.apcata.2012.02.036

Cited by 16 publications

(11 citation statements)

References 42 publications

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“…SEM studies give further information on the morphology and microstructure of the prepared N-MWNTs. Figure 1 is a typical magnification HRTEM image of the synthesized product showing the bamboo-shaped MWNTs with 97% purity and high selectivity (approximately 12 to 100 nm) with an outer diameter around 40 nm [ 19 , 20 ].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of HDPE/N-MWNT nanocomposite films

et al. 2014

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In this work, a series of nitrogen-doped multi-walled carbon nanotubes (N-MWCNTs) with several weight percentages (0.1, 0.4, 0.8, and 1.0 wt.%) were synthesized by catalytic chemical vapor deposition (CCVD) technique. The N-MWCNTs were first characterized and then dispersed in high-density polyethylene (HDPE) polymer matrix to form a nanocomposite. The HDPE/N-MWCNT nanocomposite films were prepared by melt mixing and hot pressing; a good dispersion in the matrix and a good N-MWCNT-polymer interfacial adhesion have been verified by scanning electron microscopy (SEM). Raman spectroscopy measurements have been performed on prepared samples to confirm the presence and nature of N-MWNTs in HDPE matrix. The X-ray diffraction (XRD) analysis demonstrated that the crystalline structure of HDPE matrix was not affected by the incorporation of the N-MWNTs.

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Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of HDPE/N-MWNT nanocomposite films

et al. 2014

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“…The schematic diagram for the preparation process of activated carbons is shown in Figure S1 (Supporting Information). For the second type of precursor sample, graphene prepared by chemical vapor deposition (CVD) 35 at lab scale was introduced to the initial mixture of PVP and PVA (4:6) and all composition was subjected to microwave irradiation. The cross-linked hydrogel material exhibited a consistent structure with or without graphene incorporated into it.…”

Section: Methodsmentioning

confidence: 99%

Tuning the Nanoporous Structure of Carbons Derived from the Composite of Cross-Linked Polymers for Charge Storage Applications

Barzegar

Павленко

Zahid

et al. 2021

ACS Appl. Energy Mater.

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Controlling the porosity of carbon-based electrodes is key toward performance improvement of charge storage devices, e.g., supercapacitors, which deliver high power via fast charge/discharge of ions at the electrical double layer (EDL). Here, eco-friendly preparation of carbons with adaptable nanopores from polymers obtained via microwave-assisted cross-linking of poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) is reported. The polymeric hydrogels possess porous and foam-like structures, giving excellent control of porosity at the precursor level, which are then subjected to activation at high temperatures of 700–900 °C to prepare carbons with a surface area of 1846 m 2 g –1 and uniform distribution of micro-, meso-, and macropores. Then, graphene as an additive to hydrogel precursor improves the surface characteristics and elaborates porous texture, giving composite materials with a surface area of 3107 m 2 g –1 . These carbons show an interconnected porous structure and bimodal pore size distribution suitable for facile ionic transport. When implemented in symmetric supercapacitor configuration with aqueous 5 mol L –1 NaNO 3 electrolyte, a capacitance of 163 F g –1 (per average mass of one electrode) and stable evolution of capacitance, coulombic, and energy efficiency during 10 000 galvanostatic charge/discharge up to 1.6 V at 1.0 A g –1 have been achieved.

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“…Previous works on the CVD growth of CNTs using pre-deposited catalysts showed that the CNT morphology and crystalline structure can be greatly influenced by hydrogen flow rates [19]. Some studies revealed synergistic effects between hydrogen and carbon precursor in the CNT growth process [20], while other reports indicated that hydrogen can etch pyrolytic carbon from the catalyst surface, thus prolonging the catalyst activity [21]. These observations motivate a detailed investigation of the role of hydrogen on the FCCVD synthesis of CNTs.…”

Section: Introductionmentioning

confidence: 93%

Control of product nature and morphology by adjusting the hydrogen content in a continuous chemical vapor deposition process for carbon nanotube synthesis

Dichiara

et al. 2016

Carbon

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Floating catalyst chemical vapor deposition (FCCVD) is commonly considered as one of the most attractive process for the production of carbon nanotubes (CNTs). Understanding the phenomena occurring during the FCCVD synthesis of CNTs is critical to improve the process selectivity and scalability. The present work correlates information on gas chemistry and structural characteristics of the carbonaceous products, and show how both are strongly related to the hydrogen content in the reactor. Hydrogen plays different roles in the CNT growth process whose contributions depend on the synthesis conditions. Its presence induces an augmentation in carbon supply by promoting the decomposition of hydrocarbon vapors into more reactive byproducts, and by serving as an activation agent for the dissociation of physisorbed hydrocarbons on the surface of catalyst particles. However, high hydrogen content can induce catalytic hydrogenation of carbon and lead to surface modification of CNTs. Hydrogen also interferes with the decomposition of catalytic precursors, thus influencing the size and availability of catalyst nanoparticles. As a result, the mean and core diameters, crystallinity of the graphene walls, and length of CNTs are greatly influenced by the hydrogen flow, which offers the possibility to tune the CNT properties in a very simple, yet efficient way.

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Influence of ethanol in the presence of H2 on the catalytic growth of vertically aligned carbon nanotubes

Cited by 16 publications

References 42 publications

Synthesis and characterization of HDPE/N-MWNT nanocomposite films

Synthesis and characterization of HDPE/N-MWNT nanocomposite films

Tuning the Nanoporous Structure of Carbons Derived from the Composite of Cross-Linked Polymers for Charge Storage Applications

Control of product nature and morphology by adjusting the hydrogen content in a continuous chemical vapor deposition process for carbon nanotube synthesis

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