Mapping the transition from catalyst-pool to bamboo-like growth-mechanism in vertically-aligned free-standing films of carbon nanotubes filled with Fe3C: The key role of water

Filippo S Boi,Shanling Wang,Yi He

doi:10.1063/1.4960456

Abstract

The control of carbon nanotube growth has challenged researchers for more than a decade due to the complex parameters-control necessary in the commonly used CVD approaches. Here we show that a direct transition from the catalyst-pool growth mechanism characterized by graphene-caps in the direction of growth to a bamboo-shaped mechanism characterized by the repetition of periodic elongated graphitic compartments is present when controlled quantities of water are added to ferrocene/dichlorobenzene. Our results suggest that water-addition allows enhancing the level of stress accumulated under the graphitic nanotubes-cap.

Highlights

The control of carbon nanotube growth has challenged researchers for more than a decade due to the complex parameters-control necessary in the commonly used CVD approaches
We show that a direct transition from the catalyst-pool growth mechanism characterized by graphene-caps in the direction of growth to a bambooshaped mechanism characterized by the repetition of periodic elongated graphitic compartments is present when controlled quantities of water are added to ferrocene/dichlorobenzene
In particular previous literature works have shown that four main growth mechanism can be used to describe the morphological arrangement of CNTs films depending on the used precursors or on the growth conditions: 1) the temperature gradient method in which the local temperature gradient at the open-tip of the forming CNTs favour the formation of continuous filling rates of the CNT-capillary in the order of tens of micrometres.[20]

Summary

Introduction

The control of carbon nanotube growth has challenged researchers for more than a decade due to the complex parameters-control necessary in the commonly used CVD approaches.

Results

Conclusion