Functionalization of graphene sheets through fullerene attachment

Fullerene-functionalized graphene shows a hierarchical structure, and is promising for many potential applications. In this paper, a new method is presented to synthesize such a novel nanostructure. Graphite flakes were intercalated to graphite oxide, and then functionalized with zero-dimensional fullerene nanocrystals. The resultant compounds were characterized by FT-IR spectroscopy, UV-Vis spectroscopy, atomic force microscopy, and transmission electron microscopy. The characterization results confirmed that fullerene crystals were successfully attached onto the single-layer graphene sheets and significantly facilitated the exfoliation of graphite to monolayer graphene. The fullerene grafted on the graphene surface serves as a space impediment to prevent the re-stacking of exfoliated graphene sheets. This attempt provides an effective route for large-scale exfoliation and functionalization of monolayer graphene, and is expected to significantly facilitate the application of graphene in the electronic devices, energy storage, and functional materials.