SiC formation on the carbon nanotube decorated with silicon nanoparticles

Abstract

Ex situ methods (TEM, XRD, and Raman spectroscopy) have been used to study the processes occurring at the multi-walled carbon nanotube/silicon interfaces (MWCNT/Si) during heat treatment of MWCNT-Si composites containing highly dispersed Si particles deposited on the surface of MWCNTs by CVD method. It has been established that during heat treatment, starting from 900 °C, the formation of SiC particles occurs. A further increase in temperature leads to the formation of polycrystalline SiC particles and a significant shortening of MWCNTs due to the reaction between Si particles and the surface of MWCNTs. It is shown that one can control the size of the formed SiC crystallites by varying the time and temperature of heat treatment. The kinetic dependences of the SiC formation process were studied within the Avrami-Erofeev model. The activation energy for the formation of SiC is estimated at 470 kJ/mol. The influence of heat treatment on the electrical conductivity and porosity of MWCNT-Si composites in the pressure range of 25–175 MPa has been studied.