Assembly of carbon nanotubes and alkylated fullerenes: nanocarbon hybrid towards photovoltaic applications

Abstract

Taking advantage of the non-covalent interaction between alkyl chains and the sidewalls of a singlewalled carbon nanotube (SWCNT), a nanocarbon hybrid of SWCNT and a fullerene (C 60 ) derivative with long alkyl chains was constructed as a donor-acceptor pair for photovoltaics and nanodevice investigations. It was found that SWCNT could be mostly unbundled by the alkylated C 60 (1) and was well-dispersed in organic solvents. As a photoactive material, the resultant nanocarbon hybrid, 1-SWCNT, performed well in light-energy harvesting applications in photoelectrochemical cells and nanoscale field-effect transistors (FET). Moreover, the 1-SWCNT assembly exhibited superhydrophobicity, providing an interesting opportunity to fabricate nanocarbon-based waterproof optoelectronic devices. In order to understand the photoexcitation process, the 1-SWCNT assembly was electrochemically and spectroscopically characterized. The electrochemical results showed that the SWCNT facilitated electronic communication between 1 and the electrode. The steady-state and timeresolved fluorescence and the photoluminescence excitation studies suggested efficient quenching of the singlet excited state of C 60 . Nanosecond transient absorption data revealed the one-electron reduction of fullerene, C 60 _ À , thereby demonstrating the photoinduced electron transfer from SWCNT to the C 60 unit in the 1-SWCNT assembly.

Single-walled carbon nanotubes as optical probes for bio-sensing and imaging

“…One strategy to solubilize SWCNTs is to add surfactants such as sodium dodecyl sulfate (SDS) to water so that the surfactant molecules can adsorb onto the hydrophobic nanotube sidewall. [18][19][20] Aromatic chemicals can bind to graphene and SWCNTs via π-π stacking. 1D), thus forming stable nanotube solution.…”

Exfoliation of Graphene and Assembly Formation with Alkylated‐C60: A Nanocarbon Hybrid towards Photo‐Energy Conversion Electrode Devices

“…As we reported recently, SWCNTs are mostly unbundled due to the assembly with 1 and well‐dispersed in organic solvents, i.e., chloroform and tetrahydrofuran (THF), because of a proper affinity of 1 , especially the attached long alkyl chains, toward the sidewalls of SWCNTs . Moreover, 1 also can align on the surface of graphite forming perfectly straight, submicrometer long C 60 nanowires, due to appropriate lattice matching between the graphite surface and the extended conformation of oligo‐methylene units .…”

“…By analogy to the aforementioned graphene and metallic oxide composites, the hybrids of graphene and fullerenes is expected to create a new class of active materials with the strong electron‐accepting capability characteristic of fullerenes and the good charge transport properties associated with graphene. Similarly, our previous study has shown that the assembly of C 60 derivatives and single‐walled carbon nanotubes (SWCNTs) are promising for photovoltaics . Compared with SWCNTs, which are 1D and a mixture of semiconducting and metallic, graphene is 2D and has purely semimetal characteristics, thus providing a more preferred geometry and a simpler electronic structure to collaborate with C 60 , promoting the charge separation and charge transfer.…”

“…The photocurrent is prompt, steady, and reproducible during repeated on/off light irradiation cycles. It is noted that the I SCC of the 1 ‐Gr/FTO electrode reaches about 40 μA cm −2 , which is ≈270‐fold higher than the photocurrent of the 1 /FTO electrode, and also 70% higher than that obtained by applying SWCNTs as an electron transporter in a similar electrode system . To explore the reason for the photocurrent enhancement, the surface area of 1 ‐Gr assembly was evaluated by Brunauer–Emmett–Teller (BET) analysis and was found to be about 136 m 2 g −1 , only about two times that of 1 assembly (58 m 2 g −1 ) (Figure S6, Supporting Information).…”

Fullerenes: Synthesis and Applications

“…Super capacitors Recent research investigations have shown that hybrid nano materials can generate synergistic and more exciting performance as electrode materials than the impact achieved by individual nano materials (Shen et al, 2011). A recent study revealed that a hybrid system composed of fullerene and graphene molecules conveyed a specific capacitance of 135.36 Fg -1 when used as electrode for super capacitors in contrast to the specific capacitance of pure graphene electrode ).…”