Carbon nanostructures and hydrogen storage

SWNTs are tubular carbon nanostructures (Fig. 10.3). They have a diameter in the order of 1 nm and can reach hundreds of micrometers in length. They tend to self-organize in bundles of hundreds of units, usually in hexagonal 

1 Carbon nanostructures. From top to bottom graphene layers (slit pores), Ceo fullerene and single wall nanotube. 

2 SEM image of a sample of the activated carbon IRH-4DD with a specific surface area of 2000 m /g. The macropores (largest pores) and the mesopores (smaller pores) can be seen. Observing the micropores would require better resolution. 

3 SEM (top) and TEM (bottom) images of a single wall nanotube sample. 

Carbon nanofibers are filamentous cylindrical or conical structures formed of various arrangements of stacked graphene sheets (as cones or cups), with a diameter ranging from one to several hundred nanometers, and lengths ranging from 1 pm to several millimeters. Nanostructured carbon foams 

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