The raw materials, condition and the method of preparing the catalysts play an important role in the growth of high quality Carbon Nanotubes by Catalytic Chemical Vapor Deposition method. In this work, the efficiency of Carbon Nanotubes growth was increased by a simple controlled preheating
of the catalyst in N2 atmosphere. Supports were prepared by mixing alumina powder with tetraethyl orthosilicate (TEOS) by a chemical method at low temperature. Afterwards, the supports were impregnated with iron. The dried and ground catalyst was heated in N2 atmosphere
at 500 °C for 1 hour followed by cooling down to room temperature. Methane was passed over the prepared catalyst bed at 900 °C. Supports, supported catalysts and Carbon Nanotubes samples have been characterized by Transmission Electron Microscopy, Scanning Electron Microscopy, Gas
Adsorption/Desorption Analysis, X-Ray Diffraction and Raman Spectroscopy. Scanning Electron Microscopy images of the nanotubes showed a drastic increase in the growth rate, length and straightness of the Nanotubes in comparison to the growth without preheating and even preheating in air atmosphere.
Raman Spectroscopy of the samples and Transmission Electron Microscopy pictures showed bundles, mostly equi-diameter Single Wall Nanotubes. In fact, the growth rate, length, and purity of the Nanotubes, also the homogeneity of the tubes improved. The conclusion can be made with the help of
proposed theory of nucleation and growth of Nanotubes based on comparative results of the characterizations with and without preheat-treatment. It seems that the preheat-treatment in N2 affected the catalyst structure and its interaction with support as well as distribution of the
catalyst particles on the support. These changes in return affect the quality and quantity of final production.
Journal for Nanoscience and Nanotechnology (JNN) is an international and multidisciplinary peer-reviewed journal with a wide-ranging coverage, consolidating research activities in all areas of nanoscience and nanotechnology into a single and unique reference source. JNN is the first cross-disciplinary journal to publish original full research articles, rapid communications of important new scientific and technological findings, timely state-of-the-art reviews with author's photo and short biography, and current research news encompassing the fundamental and applied research in all disciplines of science, engineering and medicine.