An all-carbon donor-acceptor hybrid combining graphene oxide (GO) and C 60 has been prepared. Laser flash photolysis measurements revealed the occurrence of photoinduced electron transfer from the GO electron donor to the C 60 electron acceptor in the conjugate.Owing to their remarkable electronic properties, the various allotropic forms of carbon have attracted an enormous attention in the field of materials science. 1 For example, photovoltaic devices made with all-carbon thin films incorporating fullerenes, carbon nanotubes (CNTs) and graphene oxide have shown promising efficiencies for light to electrical energy conversion. 2 In this particular case, the all-carbon nanocomposites were co-assembled in water to yield stable colloidal dispersions for thin film processing. 2 On the other hand, covalent hybrid nanostructures combining fullerenes and CNTs 3 were prepared and incorporated into photovoltaic 3 or optical limiting devices. 4 C 60 has also been grafted onto graphene surfaces. 5 Interestingly, such conjugates have shown enhanced nonlinear optical performances when compared to their individual components. 5b In another example, graphene oxide (GO) has been decorated with both C 60 and Zn(II)-phthalocyanines (ZnPc). 6a Photophysical studies have revealed the occurrence of photoinduced electron transfer (PET) from the ZnPc donor to the C 60 acceptor suggesting that the GO scaffold is capable of mediating the electron transfer events involving the two other partners. 6a Recently, the electron-donating behaviour of few-layer graphene in covalent ensembles with electron-accepting phthalocyanines have also been shown. 6b The possibility to use GO as an electroactive component, 7,8 namely as an electron donor, in a GO-C 60 conjugate, remains an open question. To answer this question, we now report the synthesis and the photophysical properties of a covalent GO-C 60 conjugate. Indeed, laser flash photolysis investigations revealed effectively the occurrence of PET from the modified GO sheets to the fullerene, thus demonstrating the possibility to develop covalent photoresponsive nanoconstructs exclusively based on carbon materials.The preparation of the covalent graphene oxide-[60]fullerene conjugate (GO-C 60 ) is depicted in Fig. 1. The starting GO was purchased from Nanoinnova Technologies. 9 It was then modified with 4-(trimethylsilyl)ethynylaniline via an aryl diazonium salt reaction, 10 to yield GO-TMS. Subsequent cleavage of the TMS groups using tetra-n-butylammonium fluoride (TBAF) gave GO-CCH. Finally, fullerene building block 1 11 was grafted onto the modified GO scaffold using the Cu-catalysed alkyne-azide cycloaddition (CuAAC) reaction under the conditions optimized for the grafting of fullerenecontaining azide onto carbon nanohorns 11 [CuSO 4 Á5H 2 O, sodium ascorbate in N-methyl-pyrrolidone (NMP)] (see ESI †). The resulting GO-C 60 conjugate forms stable suspensions in solvents such as DMF, NMP and CH 2 Cl 2 (Fig. S1, ESI †). The GO-C 60 hybrid obtained was characterized by Fourier-transforme...

Since fullerenes and carbon nanotubes (CNTs) were discovered, these materials have attracted a great deal of attention in the scientific community due to their unique structures and properties. The properties of both carbon allotropes can be modulated by chemical functionalization, and merging fullerenes and CNTs combines the electronic and optical properties of CNTs with the excellent electron acceptor characteristic of fullerenes; moreover, a synergistic effect of these hybrids can be found, as the properties of both the nanotube and the fullerene are affected by the presence of the other. In these hybrids, the fullerene can be located inside (endohedral) or outside (exohedral) the CNT and both types of hybrid have specific features. CNT-fullerene hybrids have been studied for various applications, including photovoltaics, optical limiting and flame retardancy amongst others. This review outlines the progress in research on CNT-fullerene hybrids, including endohedral and exohedral combinations, their properties, functionalization, applications and outlook.

A supramolecular assembly of zinc porphyrin-carbon nanohorns (CNHs) was constructed in a polar solvent. An ammonium cation was covalently connected to the CNH through a spacer (sp) (CNH-sp-NH(3)(+)) and bound to a crown ether linked to a zinc porphyrin (Crown-ZnP). Nanohybrids CNH-sp-NH(3)(+);Crown-ZnP and CNH-sp-NH(3)(+) were characterized by several techniques, such as high-resolution transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. The photoinduced electron-transfer processes of the nanohybrids have been confirmed by using time-resolved absorption and fluorescence measurements by combining the steady-state spectral data. Fluorescence quenching of the ZnP unit by CNH-sp-NH(3)(+) has been observed, therefore, photoinduced charge separation through the excited singlet state of the ZnP unit is suggested for the hybrid material, CNH-sp-NH(3)(+);Crown-ZnP. As transient absorption spectral experiments reveal the formation of the radical cation of the ZnP unit, electron generation is suggested as a counterpart of the charge-separation on the CNHs; such an electron on the CNHs is further confirmed by migrating to the hexylviologen dication (HV(2+)). Accumulation of the electron captured from HV(*+) is observed as electron pooling in solution in the presence of a hole-shifting reagent. Photovoltaic performance with moderate efficiency is confirmed for CNH-sp-NH(3)(+);Crown-ZnP deposited onto nanostructured SnO(2) films.

A soluble hybrid nanomaterial that combines fullerenes and carbon nanohorns (CNHs) has been prepared and fully characterized. Electrochemical investigations revealed that the CNHs modify the electron accepting ability of C(60) in the hybrid material.

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