Single-step synthesis of TiC mesocrystals on the MWCNTs surface by the pyrolysis of Cp2TiCl2

Abstract

Titanium carbide mesocrystals have been manufactured by the one-stage metalorganic chemical vapor deposition (MOCVD) technology using the pyrolysis of titanocene dichloride, Cp2TiCl2 (Cp = η5-C5H5) on the surfaces of multi-walled carbon nanotubes (MWCNTs). The initial stages of the Cp2TiCl2 gas-phase dissociation were modeled with density functional theory (DFT) calculations. A series of syntheses were carried out with a step-by-step increase of the Cp2TiCl2 amount. These experiments allows to observe intermediate stages of self-assembly of TiC mesocrystals. Thus, it was possible to identify that the decomposition of Cp2TiCl2 at 900 °C leads to the formation of TiC crystals nanoparticles with their accompanying self-assembly. As a final stage of this process, perfect mesocrystals of a cubic habit with a size of approximately 50 μm were found. The usage of powdered MWCNTs as a substrate in the chemical vapor deposition (CVD) processes provides heterogeneous conditions, which can be promising for the search for new forms of nanostructured materials.