A new understanding of carbon nanotube growth: Activation and deactivation of a catalyst

- Very different CVD behaviors of carbon nanotube growth are observed by a thermalanalysis-massspectra technique in different atmospheres (N2, H2).
- In N2 the catalyst is activated suddenly, then deactivation immediately follows, no hydrocarbon is detected in the process.
- In H2 the catalyst is activated gradually and deactivated gradually, H2 can react carbon over the catalyst, suppresses the deactivation.
- The activation and deactivation models in reduction atmosphere and inert atmosphere are put forwarded.