Single Wall Carbon Nanohorns (SWCNHs) are tiny graphene sheets, wrapped to form horn-shaped cones with a half fullerene cap, having 30-50 nm length and 2-5 nm diameter.

Their key characteristic is the tendency to group together and form aggregates (spherical clusters or bundles) like "dahlia" flowers or buds, having an overall diameter of tens/hundred nm.

Having a basic structure similar to tiny carbon nanotubes, SWCNHs maintain most of the typical properties of nanotubes: high electrical conductivity, high thermal conductivity and easiness of functionalization.

In 2007 Carbonium srl started the successfully production of SWCNHs in a pilot plant, and since January 2013 a new and innovative high yield plant is able to ensure very high production rate and top quality material. With the new plant a fine morphology-selective preparation of single-wall carbon nanohorn is now possible by driving the synthesis condition, so obtaining preponderant "seed", "dahlia" or "petal dahlia" types or even aggregates of graphene sheets.