Morphological Evolvement of Carbon Nanotubes Synthesized by Using Conducting Polymer Nanofibers

Figure 4

(a, b) TEM images of the bamboo-shaped CNTs synthesized by 60 s microwave time. The bamboo-shaped CNTs are found to grow in opposite directions from the sheet-like substrate in (a), and the growth direction is marked with red arrows. The bamboo-shaped CNTs are found to compose of one straight part with smooth and continuous tube wall and the other part with bamboo-like segmented tube walls, as shown in (b). (c, d) TEM images showing the magnified view of the bamboo-shaped CNTs. The catalyst Fe NPs can be observed at the tips of the CNTs, as shown in (c). And the growth direction of the bamboo-shaped CNTs is identified to be from the convex tails to the concave heads, as shown in (d). (e) Liquifying cascade growth mode similar to the 30 s situation is also observed for the 60 s CNTs. The cascading catalyst NPs with reducing sizes are numbered with arithmetic orders. (f) HRTEM image showing the well-stacking graphitized tube walls of the bamboo-shaped CNTs.

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