The Effect of Temperature and N₂:C₂H₂ Flow Rate on the Growth of Carbon Nanotubes Synthesized by CCVD of Acetylene on Alumina–Zirconia Matrix

Abstract

Optimum temperature and flow rate ratio was obtained to grow maximum carbon nanotubes on an alumina and zirconia support which finally will lead to better mechanical properties of ceramics. First, Al₂O₃–ZrO₂–Fe₂O₃ ceramic nanocomposites were prepared by the solution combustion synthesis method. In situ synthesis of CNT by CCVD route was implemented to achieve homogenous distribution in the alumina–zirconia matrix. To act as catalyst, Fe₂O₃ was reduced by N₂/H₂ flow rate ratio of 600/100 mL min⁻¹. Then, CNTs were in situ synthesized at 700, 800, and 900˚C and at various N₂:C₂H₂ flow rates of 600:15, 300:30, and 300:60 mL min⁻¹ to study the effects of synthesis temperature and N₂:C₂H₂ flow rate ratio on the formation of CNTs. The nanocomposite was characterized by XRD, SEM, TEM, TGA, and Raman. The results showed that the CNT yield was maximum when the N₂:C₂H₂ was 300:30 and the synthesis temperature was 800°C.

Keywords:

• carbon nanotubes
• chemical vapor deposition (CVD)
• acetylene decomposition
• synthesis temperature
• ceramic matrix