N-Doped graphene/C(60) covalent hybrid as a new material for energy harvesting applications

N-Doped graphene (N-G) was chemically functionalized by N-alkylation with the well-known electron acceptor C(60). The degree of functionalization and the key structural features of the N-G/C(60) hybrid were systematically investigated by a number of techniques including thermogravimetric analysis, X-ray photoelectron and Raman spectroscopies and transmission electron and atomic force microscopies. Absorption and electrochemical studies revealed interactions between the N-G and C(60) while the fluorescence of C(60) within the hybrid was found to be fully quenched. Evidence for the occurrence of excited state charge transfer from the singlet excited C(60) to N-G in the hybrid was obtained from femtosecond transient absorption studies covering the visible–near-IR regions. Electron-pooling experiments performed in the presence of a sacrificial electron donor and a second electron acceptor, methyl viologen, revealed the accumulation of the one-electron reduced product of methyl viologen upon continuous irradiation of the N-G/C(60) nanohybrid, thus revealing the utility of this material in photocatalytic energy harvesting applications.