High-yield synthesis of bundles of double- and triple-walled carbon nanotubes on aluminum flakes

Cunha, Thiago Henrique Rodrigues da; Oliveira, Sabrynna Brito; Martins, Icaro L.; Geraldo, Viviany; Miquita, Douglas R.; Ramos, Sérgio L. L. M.; Lacerda, Rodrigo G.; Ladeira, Luiz Orlando; Ferlauto, André S.

doi:10.1016/j.carbon.2018.03.014

Cited by 17 publications

(9 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As shown in Fig. 8 e, the result of maximum strain range was 1.67%, which was little larger than that of carbon nanotube Buckypaper [ 55 ]. Meanwhile, the ultimate tensile strength reaches nearly 1 MPa.…”

Section: Resultsmentioning

confidence: 99%

Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption

et al. 2020

View full text Add to dashboard Cite

HIGHLIGHTS• High-purity (~ 99%) carbon nanocoils (CNCs) without the amorphous carbon layer were synthesized by using porous α-Fe 2 O 3 /SnO 2 catalyst.• The highest yield of the CNCs can reach ~ 9098% after a 6 h growth, which is much higher than those mentioned in previous reports.• A CNC Buckypaper was successfully prepared and utilized as an efficient adsorbent for the removal of methylene blue dye with the adsorption efficiency of 90.9%.ABSTRACT High-purity (99%) carbon nanocoils (CNCs) have been synthesized by using porous α-Fe 2 O 3 /SnO 2 catalyst. The yield of CNCs reaches 9,098% after a 6 h growth. This value is much higher than the previously reported data, indicating that this method is promising to synthesize high-purity CNCs on a large scale. It is considered that an appropriate proportion of Fe and Sn, proper particle size distribution, and a loose-porous aggregate structure of the catalyst are the key points to the high-purity growth of CNCs. Benefiting from the high-purity preparation, a CNC Buckypaper was successfully prepared and the electrical, mechanical, and electrochemical properties were investigated comprehensively.Furthermore, as one of the practical applications, the CNC Buckypaper was successfully utilized as an efficient adsorbent for the removal of methylene blue dye from wastewater with an adsorption efficiency of 90.9%. This study provides a facile and economical route for preparing high-purity CNCs, which is suitable for large-quantity production. Furthermore, the fabrication of macroscopic CNC Buckypaper provides promising alternative of adsorbent or other practical applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The XPS results in Figure 8b indicate that further reduction of Cr 3+ to Cr 0 did not happen in the CO/CH4 dry gases. These findings suggest that the FeCr catalyst formed metallic Fe nanoparticles supported on Fe 3+/2+ and Cr 6+/3+ oxides in which the oxide surface inhibited the migration and aggregation of metallic particles that may have, in turn, improved the MWCNT uniformity [37]. The spectra of S 2p in Figure 8c clearly show the peak of S 2− at 158.5-165.7 eV for the sample reacted with the 500 ppmv H 2 S but not in the sample reacted with the sulfur-free gas.…”

Section: Effects Of H2s In Feedmentioning

confidence: 94%

Carbon Nanotube Formation on Cr-Doped Ferrite Catalyst during Water Gas Shift Membrane Reaction: Mechanistic Implications and Extended Studies on Dry Gas Conversions

et al. 2020

View full text Add to dashboard Cite

A nanocrystalline chromium-doped ferrite (FeCr) catalyst was shown to coproduce H2 and multiwalled carbon nanotubes (MWCNTs) during water gas shift (WGS) reaction in a H2-permselective zeolite membrane reactor (MR) at reaction pressures of ~20 bar. The FeCr catalyst was further demonstrated in the synthesis of highly crystalline and dimensionally uniform MWCNTs from a dry gas mixture of CO and CH4, which were the apparent sources for MWCNT growth in the WGS MR. In both the WGS MR and dry gas reactions, the operating temperature was 500 °C, which is significantly lower than those commonly used in MWCNT production by chemical vapor deposition (CVD) method from CO, CH4, or any other precursor gases. Extensive ex situ characterizations of the reaction products revealed that the FeCr catalyst remained in partially reduced states of Fe3+/Fe2+ and Cr6+/Cr3+ in WGS membrane reaction while further reduction of Fe2+ to Fe0 occurred in the CO/CH4 dry gas environments. The formation of the metallic Fe nanoparticles or catalyst surface dramatically improved the crystallinity and dimensional uniformity of the MWCNTs from dry gas reaction as compared to that from WGS reaction in the MR. Reaction of the CO/CH4 mixture containing 500 ppmv H2S also resulted in high-quality MWCNTs similar to those from the H2S-free feed gas, demonstrating excellent sulfur tolerance of the FeCr catalyst that is practically meaningful for utilization of biogas and cheap coal-derived syngas.

show abstract

“…CeO 2 : 20 mol% Sm 2 O 3 (20SDC) agglomerated ceramic powders with >100 m 2 •g −1 , 5-10 nm primary crystallite size (Fuel Cell Materials, USA) were used as the matrix [59]. Multiwalled carbon nanotubes (CNT) were synthesized by catalytic chemical vapor deposition at 730 • C using ethylene as carbon source and a Fe-Co/Al 2 O 3 catalyst [60]. The CNTs have diameters ranging from 10 to 30 nm and carbon purity of 93%.…”

Section: Methodsmentioning

confidence: 99%

Flash Sintering Samaria-Doped Ceria–Carbon Nanotube Composites

2019

View full text Add to dashboard Cite

Composite ceramic green pellets were prepared by attrition milling a mixture of (CeO2)0.8(Sm2O3)0.2 (samaria-doped ceria, SDC) ceramic powder and carbon nanotubes (CNTs), followed by uniaxial and isostatic pressing. The pellets were sintered inside a dilatometer by applying AC electric fields at 850 °C and limiting the electric current to 1 A, achieving 20.2% final shrinkage. The SDC samples reached 13.3% shrinkage under the same conditions. Higher average grain sizes were measured in specimens flash sintered with CNTs. Impedance spectroscopy analyses show that the specimens flash sintered with addition of CNTs have higher electrical conductivity. Higher delivered Joule heating at the interfaces due to the presence of the electronic conductors (CNTs) are proposed as the main reason for that improvement of the electrical behavior.

show abstract

High-yield synthesis of bundles of double- and triple-walled carbon nanotubes on aluminum flakes

Cited by 17 publications

References 28 publications

Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption

Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption

Carbon Nanotube Formation on Cr-Doped Ferrite Catalyst during Water Gas Shift Membrane Reaction: Mechanistic Implications and Extended Studies on Dry Gas Conversions

Flash Sintering Samaria-Doped Ceria–Carbon Nanotube Composites

Contact Info

Product

Resources

About