Due to their small size and their extraordinary physicochemical properties [1][2][3], much attention has been paid to the interesting sp 2 -based fibrous carbons, including carbon nanotubes. It is generally accepted that carbon nanotubes consist of single or multiple graphene sheets rolled into concentric cylinders: thus giving rise to single wall carbon nanotubes (SWNTs) or multi-walled carbon nanotubes (MWNTs) [4,5]. Recently, we described a new type of carbon nanofiber, "stacked-cup carbon nanofiber", which exhibited a unique morphology of stacked, truncated conical graphene layers (cups) along the fiber length [6][7][8].Previously, three different geometries of carbon nanofibers (e.g., platelet, 1