Synthesis of multi-layer graphene and multi-wall carbon nanotubes from direct decomposition of ethanol by microwave plasma without using metal catalysts

The synthesis of nanostructured carbon materials by using microwave plasmas at atmospheric pressure is presented. This technique involves only one step and without any other supplementary chemical process or metal catalyst. Multi-layer graphene, multi-wall carbon nananotubes and H₂ were obtained by the plasma after ethanol decomposition. Strong emissions of both C₂ molecular bands and C carbon were emitted by the plasma during the process. Futhermore, plasma parameters were studied. Our research shows that both C₂ radicals and high gas temperatures (>3000 K) are required for the synthesis of these materials, which contribute to the understanding of materials synthesis by plasma processes. (fast track communication)