Influence of ethanol in the presence of H2 on the catalytic growth of vertically aligned carbon nanotubes

The vertically aligned multi-walled carbon nanotubes (VA-MWNTs) were synthesized by a catalytic chemical vapor deposition (CCVD) technique, using ferrocene as an iron catalyst precursor and toluene/ethanol mixture with different ratio as a carbon source/etching agent, in the presence of H2. The growth rate, efficiency and the structure of the synthesized tubes were investigated. The CNTs growth rate and quality of tubes significantly improve up to 9 vol.% of ethanol whereas a negative influence was observed for higher ethanol concentration (>17 vol.%). Low ethanol content in the reaction mixture (5 vol.%) results in the highest volume density of the tubes within the array along with highest specific surface area. The synergetic effect of EtOH/hydrogen on the growth rate of VA-MWNTs was observed as well.

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► We have investigated the influence of EtOH addition on the VA-CNTs growth by CVD.
► The EtOH addition up to 9% to the reaction mixture increases the CNTs growth rate.
► The EtOH addition higher than 9% decreases the CNTs growth rate.
► A structure of CNTs array and the individual tubes change with EtOH content.