Abstract: Methods for solubilizing carbon nanohorns and applications thereof, including the manufacture of composites, hydrogen storage, catalyst supports and drug delivery. In certain embodiments, the method can include: a) Reduction of pristine carbon nanohorns by an alkali metal to lead to a carbon nanohorn alkali salt; and b) Exposure of said carbon nanohorn alkali salt to a polar aprotic solvent to lead to a solution of reduced carbon nanohorns. In certain other embodiments, solutions of carbon nanohorns, and individual carbon nanohorns are obtainable by the methods, as well as uses of such individual carbon nanohorns and solutions of carbon nanohorns.