Highly efficient water-assisted synthesis of carbon nanotubes by the chemical vapor deposition method

Abstract

Carbon nanotubes (CNTs) have attracted the scientific community over two last decades. Due to their novel properties, carbon nanotubes have been applied in different areas. In this research, carbon nanotubes were synthesized on Fe/γ-Al2O3 catalyst by the chemical vapor deposition (CVD) method using liquefied petroleum gas (LPG) as a carbon source and steam instead of hydrogen in the reaction medium. The steam plays a role as a cleaning agent for the product. The CNTs yield of this synthesis process is high, up to 434% in mass in relation to the used mass of catalyst under 2 hours of synthesis. The images obtained by scanning electron microscopy (SEM) and transparent electron microscopy (TEM) showed that the obtained product was carbon nanotubes with quite homogeneous diameters. The BET specific surface area of the obtained product was determined by nitrogen isothermal adsorption-desorption using the Brunauer-Emmett-Teller method. In addition, the structural defects of CNTs were characterized by Raman spectroscopy, and the elemental composition was analyzed by X-ray electron spectroscopy (XPS).