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spelling paper:paper_09214526_v404_n18_p2795_Escobar2023-06-08T15:50:34Z Effect of catalyst preparation on the yield of carbon nanotube growth Escobar, Mariano Martín Candal, Roberto Jorge Goyanes, Silvia Nair Carbon nanotubes Catalysis Sol gel Carbon atoms Carbon nanotube growth Carbon nanotubes displays Catalyst structures Catalytic chemical vapor deposition Crystalline phasis Effect of catalyst Growth mechanisms Growth modes Hydrogen/Nitrogen Iron nanoparticles Iron nitrates Metallic iron Multi-Wall Carbon Nanotubes Room temperature Silica matrix Sol-gel methods Tetra-ethyl-ortho-silicate Acetylene Carbon nanotubes Catalysis Catalysts Chemical vapor deposition Coagulation Gelation Gels Iron analysis Iron oxides Lighting Metallic compounds Silica Sol-gels Sols Multiwalled carbon nanotubes (MWCN) Multi-wall carbon nanotubes (MWCNTs) were synthesized by catalytic chemical vapor deposition (CVD) on catalytic iron nanoparticles dispersed in a silica matrix, prepared by sol gel method. In this contribution, variation of gelation condition on catalyst structure and its influence on the yield of carbon nanotubes growth was studied. The precursor utilized were tetraethyl-orthosilicate and iron nitrate. The sols were dried at two different temperatures in air (25 or 80 °C) and then treated at 450 °C for 10 h. The xerogels were introduced into the chamber and reduced in a hydrogen/nitrogen (10%v/v) atmosphere at 600 °C. MWCNTs were formed by deposition of carbon atoms from decomposition of acetylene at 700 °C. The system gelled at RT shows a yield of 100% respect to initial catalyst mass whereas the yield of that gelled at 80 °C was lower than 10%. Different crystalline phases are observed for both catalysts in each step of the process. Moreover, TPR analysis shows that iron oxide can be efficiently reduced to metallic iron only in the system gelled at room temperature. Carbon nanotubes display a diameter of about 25-40 nm and several micron lengths. The growth mechanism of MWCNTs is base growth mode for both catalysts. Crown Copyright © 2009. Fil:Escobar, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Candal, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Goyanes, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09214526_v404_n18_p2795_Escobar http://hdl.handle.net/20.500.12110/paper_09214526_v404_n18_p2795_Escobar
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Carbon nanotubes
Catalysis
Sol gel
Carbon atoms
Carbon nanotube growth
Carbon nanotubes displays
Catalyst structures
Catalytic chemical vapor deposition
Crystalline phasis
Effect of catalyst
Growth mechanisms
Growth modes
Hydrogen/Nitrogen
Iron nanoparticles
Iron nitrates
Metallic iron
Multi-Wall Carbon Nanotubes
Room temperature
Silica matrix
Sol-gel methods
Tetra-ethyl-ortho-silicate
Acetylene
Carbon nanotubes
Catalysis
Catalysts
Chemical vapor deposition
Coagulation
Gelation
Gels
Iron analysis
Iron oxides
Lighting
Metallic compounds
Silica
Sol-gels
Sols
Multiwalled carbon nanotubes (MWCN)
spellingShingle Carbon nanotubes
Catalysis
Sol gel
Carbon atoms
Carbon nanotube growth
Carbon nanotubes displays
Catalyst structures
Catalytic chemical vapor deposition
Crystalline phasis
Effect of catalyst
Growth mechanisms
Growth modes
Hydrogen/Nitrogen
Iron nanoparticles
Iron nitrates
Metallic iron
Multi-Wall Carbon Nanotubes
Room temperature
Silica matrix
Sol-gel methods
Tetra-ethyl-ortho-silicate
Acetylene
Carbon nanotubes
Catalysis
Catalysts
Chemical vapor deposition
Coagulation
Gelation
Gels
Iron analysis
Iron oxides
Lighting
Metallic compounds
Silica
Sol-gels
Sols
Multiwalled carbon nanotubes (MWCN)
Escobar, Mariano Martín
Candal, Roberto Jorge
Goyanes, Silvia Nair
Effect of catalyst preparation on the yield of carbon nanotube growth
topic_facet Carbon nanotubes
Catalysis
Sol gel
Carbon atoms
Carbon nanotube growth
Carbon nanotubes displays
Catalyst structures
Catalytic chemical vapor deposition
Crystalline phasis
Effect of catalyst
Growth mechanisms
Growth modes
Hydrogen/Nitrogen
Iron nanoparticles
Iron nitrates
Metallic iron
Multi-Wall Carbon Nanotubes
Room temperature
Silica matrix
Sol-gel methods
Tetra-ethyl-ortho-silicate
Acetylene
Carbon nanotubes
Catalysis
Catalysts
Chemical vapor deposition
Coagulation
Gelation
Gels
Iron analysis
Iron oxides
Lighting
Metallic compounds
Silica
Sol-gels
Sols
Multiwalled carbon nanotubes (MWCN)
description Multi-wall carbon nanotubes (MWCNTs) were synthesized by catalytic chemical vapor deposition (CVD) on catalytic iron nanoparticles dispersed in a silica matrix, prepared by sol gel method. In this contribution, variation of gelation condition on catalyst structure and its influence on the yield of carbon nanotubes growth was studied. The precursor utilized were tetraethyl-orthosilicate and iron nitrate. The sols were dried at two different temperatures in air (25 or 80 °C) and then treated at 450 °C for 10 h. The xerogels were introduced into the chamber and reduced in a hydrogen/nitrogen (10%v/v) atmosphere at 600 °C. MWCNTs were formed by deposition of carbon atoms from decomposition of acetylene at 700 °C. The system gelled at RT shows a yield of 100% respect to initial catalyst mass whereas the yield of that gelled at 80 °C was lower than 10%. Different crystalline phases are observed for both catalysts in each step of the process. Moreover, TPR analysis shows that iron oxide can be efficiently reduced to metallic iron only in the system gelled at room temperature. Carbon nanotubes display a diameter of about 25-40 nm and several micron lengths. The growth mechanism of MWCNTs is base growth mode for both catalysts. Crown Copyright © 2009.
author Escobar, Mariano Martín
Candal, Roberto Jorge
Goyanes, Silvia Nair
author_facet Escobar, Mariano Martín
Candal, Roberto Jorge
Goyanes, Silvia Nair
author_sort Escobar, Mariano Martín
title Effect of catalyst preparation on the yield of carbon nanotube growth
title_short Effect of catalyst preparation on the yield of carbon nanotube growth
title_full Effect of catalyst preparation on the yield of carbon nanotube growth
title_fullStr Effect of catalyst preparation on the yield of carbon nanotube growth
title_full_unstemmed Effect of catalyst preparation on the yield of carbon nanotube growth
title_sort effect of catalyst preparation on the yield of carbon nanotube growth
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09214526_v404_n18_p2795_Escobar
http://hdl.handle.net/20.500.12110/paper_09214526_v404_n18_p2795_Escobar
work_keys_str_mv AT escobarmarianomartin effectofcatalystpreparationontheyieldofcarbonnanotubegrowth
AT candalrobertojorge effectofcatalystpreparationontheyieldofcarbonnanotubegrowth
AT goyanessilvianair effectofcatalystpreparationontheyieldofcarbonnanotubegrowth
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