Evidence for growth mechanism and helix-spiral cone structure of stacked-cup carbon nanofibers

New evidence for the structure of Ni-catalyzed stacked-cup carbon nanofibers (CNFs) has been found. This type of carbon nanofiber exhibits a wide hollow core as well as a large diameter (between 40 and 140 nm). The fibers have been produced by the floating catalyst method using natural gas as carbon...

Full description

Saved in:
Bibliographic Details
Published in:Carbon (New York) 2007-11, Vol.45 (14), p.2751-2758
Main Authors: Vera-Agullo, Jose, Varela-Rizo, Helena, Conesa, Juan A., Almansa, Cristina, Merino, César, Martin-Gullon, Ignacio
Format: Article
Language:English
Subjects:
Cross-disciplinary physics: materials science
rheology
Exact sciences and technology
Fullerenes and related materials
diamonds, graphite
Materials science
Physics
Specific materials
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:New evidence for the structure of Ni-catalyzed stacked-cup carbon nanofibers (CNFs) has been found. This type of carbon nanofiber exhibits a wide hollow core as well as a large diameter (between 40 and 140 nm). The fibers have been produced by the floating catalyst method using natural gas as carbon feedstock, a sulfur compound, and a nickel catalyst. It was found that the catalytic particles are heterogeneous with two different parts: one composed of metallic Ni, which is the catalytically active portion of the particle, and another composed of NiS, which allows for the hollow nanofiber structure. The hollow core of the fibers has similar dimensions to the NiS volume of the particle and the graphitic layers grow from the rear nickel region of the particle. Nevertheless, the NiS component seems to be indispensable in producing the helix-spiral formation of the graphitic structure, as clearly shown by the TEM studies.
ISSN:0008-6223
1873-3891
DOI:10.1016/j.carbon.2007.09.040