The unifying objective of this thesis is to synthesize, control, modify, hybridize, interface, understand, and apply one- and two-dimensional sp2-carbon nanomaterials. The materials include graphene (2D), carbon nanotubes (1D), and graphene nanoribbons (pseudo-1D); and their hybrids with each other. Other classes of materials such as molecules, polymers, and inorganic nanoparticles are also interfaced with the carbon materials. This thesis uncovers, demonstrates, and elucidates methods to (1) synthesize graphene with different number of layers; (2) to produce a full Li-ion battery based on a hybrid of graphene and carbon nanotubes; (3) to prepare a Li-ion battery electrode made from a composite of graphene nanoribbon (GNR) stacks and iron oxide nanoparticles; (4) to prepare an oxygen reduction reaction catalyst made from a composite of GNR stacks and silver nanoparticles; (5) to fabricate a conductive composite of GNR stacks and epoxy and employ it for Joule heating and deicing of surfaces; (6) to generate sprayable, electrically conductive, and radiofrequency transparent films made using functionalized GNR stacks for de-icing application; and (7) to produce conductive GNR films that are simultaneously radiofrequency and optically transparent. The various materials developed demonstrate the versatility of sp2-carbon in terms of synthesis, properties, and applications.