title: Shape-Controlled Growth of Carbon Nanostructures: Yield and Mechanism.
abstract: Carbon nanostructures with precisely controlled shapes are difficult materials to synthesize. A facet-selective-catalytic process was thus proposed to synthesize polymer-linked carbon nanostructures with different shapes, covering straight carbon nanofiber, carbon nano Y-junction, carbon nano-hexapus, and carbon nano-octopus. A thermal chemical vapor deposition process was applied to grow these multi-branched carbon nanostructures at temperatures lower than 350 °C. Cu nanoparticles were utilized as the catalyst and acetylene as the reaction gas. The growth of those multi-branched nanostructures was realized through the selective growth of polymer-like sheets on certain indexed facets of Cu catalyst. The vapor-facet-solid (VFS) mechanism, a new growth mode, has been proposed to interpret such a growth in the steps of formation, diffusion, and coupling of carbon-containing oligomers, as well as their final precipitation to form nanostructures on the selective Cu facets.
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany).
authors.forename: Yao
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany).
authors.forename: Xiao
authors.initials: X
authors.lastname: Sun
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany). nianjun.yang@uni-siegen.de.
authors.forename: Nianjun
authors.initials: N
authors.lastname: Yang
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany).|Peter Grünberg Institute and Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Jülich 52425 (Germany).
authors.forename: Junhai
authors.initials: J
authors.lastname: Xia
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany).|Peter Grünberg Institute and Ernst Ruska-Centre (ER-C) for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Jülich 52425 (Germany).
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Materials Engineering, University of Siegen, Paul-Bonatz Str. 9-11, 57076, Siegen (Germany). xin.jiang@uni-siegen.de.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
keywords: Cu catalyst; carbon nanostructures; chemical vapor deposition; growth mechanism; shape control