Separation of Semiconducting from Metallic Carbon Nanotubes by Selective Functionalization with Azomethine Ylides

Ménard‐Moyon, Cécilia; Izard, Nicolas; Doris, Eric; Mioskowski, Charles

doi:10.1021/ja060802f

Cited by 120 publications

(78 citation statements)

References 14 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Metallic tubes were also reported preferentially etched away by water and methane plasma because of their higher reactivity (13,14). On the other hand, H 2 O 2 (15), azomethineylides (16), and gaseous SO 3 (17) preferentially attacked s-SWCNTs, and recently s-SWCNTs were also shown to be preferentially polycarboxylated via reductive sidewall functionalization (18). However, it has not been studied yet if confinement of metal cluster catalysts within metallic and semiconducting SWCNTs affects chemical reactions differently.…”

mentioning

confidence: 99%

Tuning the redox activity of encapsulated metal clusters via the metallic and semiconducting character of carbon nanotubes

Zhang

Pan

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We demonstrate that reactions confined within single-walled carbon nanotube (SWCNT) channels are modulated by the metallic and semiconducting character of the hosts. In situ Raman and X-ray absorption near-edge structure spectroscopies provide complementary information about the electronic state of carbon nanotubes and the encapsulated rhenium species, which reveal electronic interactions between encapsulated species and nanotubes. More electrons are transferred from metallic tubes (m-SWCNTs) to oxidic rhenium clusters, leading to a lower valence state rhenium oxide than that in semiconducting tubes (s-SWCNTs). Reduction in 3.5% (vol/vol) H 2 /Ar leads to weakened host-guest electronic interaction. The high valence state Re within s-SWCNTs is more readily reduced when raising the temperature, whereas only a sluggish change is observed for Re within m-SWCNTs. Only at 400°C does Re reach a similar electronic state (mixture of Re 0 and Re 4+ ) in both types of tubes. Subsequent oxidation in 1% O 2 /Ar does not show changes for Re in s-SWCNTs up to 200°C. In comparison, m-SWCNTs facilitate the oxidation of reduced rhenium (160°C). This can be exploited for rational design of active catalysts with stable species as a desired valence state can be obtained by selecting specific-type SWCNTs and a controlled thermal treatment. These results also provide a chemical approach to modulate reversibly the electronic structure of SWCNTs without damaging the sidewalls of SWCNTs.confined catalysis | confinement effect A n increasing number of studies reveal that confinement of metal or metal oxide nanoparticles inside carbon nanotubes (CNTs) often leads to significantly enhanced catalytic activity with respect to the same bare metal nanoparticles or those deposited on the outer walls of CNTs (1-3). Such a different behavior originates from both the physical (spatial restriction of the channels) and chemical factors (electronic interaction of confined species with the curved graphene walls) inside CNTs (1-5). In this sense, single-walled carbon nanotubes (SWCNTs) are very interesting because they have a higher degree of uniformity and smaller channel compared with multiwalled CNTs (6). More interestingly, they exhibit intrinsically either metallic or semiconducting properties with different electronic structure around the Fermi level. Metallic and semiconducting SWCNTs (m-SWCNTs and s-SWCNTs, respectively) have been demonstrated to vary significantly in reactivity toward covalent and noncovalent functionalization of their sidewalls (7-9). For example, diazonium salts (10), nitronium ions (NO 2 + ) (11), and OsO 4 (12) reacted selectively with metallic tubes, which was attributed to their higher electron density near the Fermi level. Metallic tubes were also reported preferentially etched away by water and methane plasma because of their higher reactivity (13,14). On the other hand, H 2 O 2 (15), azomethineylides (16), and gaseous SO 3 (17) preferentially attacked s-SWCNTs, and recently s-SWCNTs were also shown to be preferentially...

show abstract

mentioning

confidence: 99%

Tuning the redox activity of encapsulated metal clusters via the metallic and semiconducting character of carbon nanotubes

Zhang

Pan

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…1a) This was the first demonstrated method of sorting by electronic type [59]. In this method, a surfactant-stabilized aqueous suspension of single-wall carbon nanotubes is placed onto an array of interdigitated electrodes, across Dielectrophoresis [59][60][61][62][63][64][65][66][67] Electrophoresis [58] Noncovalent adsorption RNH2 (THF) 2 + filtration [68,69]; + centrifugation [70,71] Van der Waals Extraction TOAB (H2O/EA) 3 [72] Encapsulation of metallocenes [73] Reversible cyclic peptides + centrifugation [74] Charge transfer Br2 + centrifugation [75] Electrochemical doping [76] FeCl3 [77,78] K [77,78] π stacking Porphyrins + centrifugation [79] DNA + centrifugation [80] Reversible covalent functionalization [81] Chemical reaction OsO4 + hν [82] Chemical decomposition RN + 2 (l/s) [83] H2O2 [84] H plasma [85] CH4 plasma (g) [86] HNO3 [87] O2 (g) [87] H2SO4/H2O2 [88] Physical destruction Electrical breakdown (g/s) [89,90] Notes:…”

Section: Nondestructive Sortingmentioning

confidence: 99%

Carbon Nanotube Synthesis and Organization

Joselevich

Dai

Liu

et al. 2007

Topics in Applied Physics

122

View full text Add to dashboard Cite

Abstract. The synthesis, sorting and organization of carbon nanotubes are major challenges toward future applications. This chapter reviews recent advances in these topics, addressing both the bulk production and processing of carbon nanotubes, and their organization into ordered structures, such as fibers, and aligned arrays on surfaces. The bulk synthetic methods are reviewed with emphasis on the current advances toward mass production and selective synthesis. New approaches for the sorting of carbon nanotubes by structure and properties are described in the context of the specific physical or chemical interactions at play, and referring to the characterization methods described in the contribution by Jorio et al. Recent advances in the organization of carbon nanotubes into fibers are reviewed, including methods based on spinning from solution, from dry forests, and directly from the gas phase during growth. The organization of carbon nanotubes on surfaces, as a critical prerequisite toward future applications in nanoelectronics, is reviewed with particular emphasis given to the synthesis of both vertically and horizontally aligned arrays. Vertically aligned growth has been recently boosted by the development of highly efficient catalytic processes. Horizontally aligned growth on surfaces can yield a whole new array of carbon-nanotube patterns, with interesting physical properties and potential applications. Different mechanisms of horizontally aligned growth include field-and flow-directed growth, as well as recently developed methods of surface-directed growth on single-crystal substrates by epitaxial approaches. The proposed mechanisms pertinent to each technique are discussed throughout this review, as well as their potential applications and critical aspects toward future progress.

show abstract

“…Covalent and non-covalent chemical functionalization approaches play a fundamental role to debundle and stabilize CNTs in solution where their unique characteristics can be discerned and studied. Reagents, such as oxidants [6], diazonium salts [7][8], carbenes [9], nitronium ions [10], lithium alkynylides [11], and azomethine ylides [12], have been successfully employed for the covalent modification of CNTs. Despite this rich functionalization chemistry [13][14][15][16][17], only a few comparative studies [11,18] on the addition chemistry to CNT have been reported so far.…”

Section: Introductionmentioning

confidence: 99%

Chemistry of Carbon Nanotubes in Flow

Salice¹,

Rossi²,

Pace³

et al. 2014

J Flow Chem

View full text Add to dashboard Cite

The covalent chemistry of carbon nanostructures has put forth a wide variety of interesting derivatives that widen their potential as functional materials. However, the synthetic procedures that have been developed to functionalize the nanostructures may require long reaction times and harsh conditions. In this paper, we study the continuous flow processing of single-wall carbon nanotubes with azomethine ylides and diazonium salts and demonstrate that this approach is effective to reduce reaction times and tune the properties of the functionalized carbon materials.

show abstract

Separation of Semiconducting from Metallic Carbon Nanotubes by Selective Functionalization with Azomethine Ylides

Cited by 120 publications

References 14 publications

Tuning the redox activity of encapsulated metal clusters via the metallic and semiconducting character of carbon nanotubes

Tuning the redox activity of encapsulated metal clusters via the metallic and semiconducting character of carbon nanotubes

Carbon Nanotube Synthesis and Organization

Chemistry of Carbon Nanotubes in Flow

Contact Info

Product

Resources

About