Synthesis of Carbon Nanotube-Carbon Nanosphere on the CF Surface by CVD

Abstract

In the current work, the synthesis of carbon nanotubes (CNTs) and carbon nanospheres (CNS’s) has been investigated by applying the chemical vapor deposition method in a one-step sample preparation. In this method, iron nitrate non-hydrate (Fe(NO3)3.9H2O) and acetylene (C2H2) have been used as the catalyst source and carbon source, respectively, to grow CNT directly on the CF surface at 700°C and then CNS’s were synthesized on the CNT layers at 900°C under a 250sccm gas flow rate (40%N2, 40%H2, 20% C2H2). According to the SEM and TEM micrographs from the resultant carbon nanoparticles, the diameters of the CNTs and CNS’s have been estimated about 30-50nm and 300-400nm, respectively.

Carbon–Carbon Allotropic Hybrids and Composites: Synthesis, Properties, And Applications

“…Such CVD process is normally a one-step only, as for example the formation of CNSs/CNTs using acetylene as carbon precursor and iron nitrate as the catalyst precursor, when CNTs are produced at 700 °C from C 2 H 2 , whereas CNs form at 900 °C from a C 2 H 2 +N 2 +H 2 mixture. 87 As was elucidated in a report, 88 the nanospheres, coating CNTs, can be composed of graphene nanoparticles and are seamlessly connected with graphene stacks. Carbon nanospheres can be formed in three steps, described by authors: "(a) the formation of graphene nanoparticle on the CNTs surface and on the silicon substrate, (b) the migration of active hydrocarbon groups towards the surface of the CNTs deposition zone at high temperature, and (c) the formation of carbon nanospheres by the aggregating hydrocarbon active groups.…”

“…This composite was found to have supercapacitor properties, whose functional principle is based on the hanging CNSs for ion accumulation, while the CNT backbone provides route channels for faster ion diffusion. Such CVD process is normally a one-step only, as for example the formation of CNSs/CNTs using acetylene as carbon precursor and iron nitrate as the catalyst precursor, when CNTs are produced at 700 °C from C 2 H 2 , whereas CNs form at 900 °C from a C 2 H 2 +N 2 +H 2 mixture . As was elucidated in a report, the nanospheres, coating CNTs, can be composed of graphene nanoparticles and are seamlessly connected with graphene stacks.…”

“…Schematic illustration of the synthesis process of GO/CDs composites. Reprinted with permission from ref . Copyright 2017 Elsevier.…”

Preparation of catalyst from natural montmorillonite mineral and its application in the synthesis of carbon nanosphere

“…It is possible to change a surface by attaching a carboxyl or hydroxyl group and increasing the hydrophilic property of the material, allowing CNS to be used in an even broader range of applications. In addition, most studies on carbon nanosphere synthesis used chemical-grade precursors as a catalyst for the chemical vapour deposition (CVD) method [11]. There have only been a few attempts to use natural minerals such as laterite and kaolin as a substrate or catalyst in the synthesis of carbon nanospheres but montmorillonite [12,13].…”