fullerene vs nanotube

fullerene and nanotube both are nouns.

Word	Noun	Adjective	Verb	Adverb
fullerene	Yes	No	No	No
nanotube	Yes	No	No	No

As nouns, nanotube is a hyponym of fullerene; that is, nanotube is a word with a more specific, narrower meaning than fullerene:

fullerene: a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms
nanotube: a fullerene molecule having a cylindrical or toroidal shape

Other hyponyms of fullerene include buckminsterfullerene, buckyball, carbon nanotube.

fullerene (noun)	nanotube (noun)
a form of carbon having a large molecule consisting of an empty cage of sixty or more carbon atoms	a fullerene molecule having a cylindrical or toroidal shape