Observation of carbon nanotubes synthesized on various substrates using metal-phthalocyanine

Multiwalled carbon nanotubes (MWNT) were synthesized on various substrates by vacuum chemical vapour deposition at 700-750 degreesC using (Co, Ni, Fe)-phthalocyanines (Pcs) as source materials. Intense growth was observed on a quartz plate with a low surface tension and an oxidized surface of an Al plate. Nanotubes grew only at the micro-defects of Ni, Fe and stainless foils and only at uneven sites of Ta and W foils. No growth was observed on a smooth area of Ta and W foils with large surface tensions. When vapours of these metals impinge onto the substrate from the vapour phase, they may aggregate to a nanometer-sized particle with a high contact angle against the substrate because of their hard wetting, and nucleation of MWNTs may occur on the particle. We also performed CVD synthesis of MWNTs in a H-2/Ar gas flow. When FePc was used as source material, uniformly aligned nanotubes grew at the edges of a quartz plate and the inner wall of a quartz tube.