Fig 4 - uploaded by Shashank Misra
Content may be subject to copyright.
Model calculation of the electronic structure of a peapod. The model Hamiltonian used in these calculations has the form H 1 a dx † (x)H 0 (x) n a c c(x na) [ † (na) T ˆ † (x) † (x) T ˆ (na)]
Source publication
Arrays of C60 molecules nested inside single-walled nanotubes represent a class of nanoscale materials having tunable properties. We report electronic measurements of this system made with a scanning tunneling microscope and demonstrate that the encapsulated C60 molecules modify the local electronic structure of the nanotube. Our measurements and c...
Similar publications
Single wall carbon nanotubes (SWCNTs) are archetypical 1D systems with peculiar electronic properties which can be modified in a controlled manner by various methods. One of these is filling the hollow core with metallofullerenes. Additionally, subsequent modifications can be induced utilizing the nanotube hollow space as a nano-reactor. Here we sh...
Density functional calculations of the electronic structure of the Fe-12 cluster encapsulated inside finite single-wall zigzag carbon nanotubes of indices (11,0) and (10,0) have been performed. Several Fe-12 isomers have been considered, including elongated shape isomers aimed to fit well inside the nanotubes, and the icosahedral minimum energy str...
Ab initio electronic structure calculations based on density functional theory are performed for SinFe clusters to determine stable structures. Our results show that these clusters can form the building block for Fe-encapsulated Si-nanotubes. The Si10Fe and Si12Fe clusters are found to be very stable, exhibiting large charge transfer, and can lead...
Citations
... Accordingly, carbon nanotubes acting as nano-containers [9] and nano-reactors [10] have become a hot topic in terms of the exploitation and modification of their excellent electronic [11] and mechanical properties [12] in nanomaterial science. It is well established that the fullerene dopants can modify the electronic structures of SWCNTs [13][14][15] and lead to advantageous physical and chemical properties that could be utilized in many applications, such as nanoelectronics [16,17], quantum computing [15,18], and thermoelectricity [19,20]. ...
Carbon nano peapods, with their electronic properties and spintronics, have attracted great attention regarding their potential applications when combined with fullerenes or their derivatives encapsulated inside. Herein, we have designed and synthesized a series of fullerene derivatives with different functional groups, which are then encapsulated into single-walled carbon nanotubes (SWCNTs). Accurate morphological characterization with high-resolution TEM reveals a clear correlation between the filling ratio of the peapods and the steric bulk of the functionalized groups. Further spectroscopic characterizations reveal diameter-selective interactions between the fullerene derivatives and SWCNTs, which, in turn, influence the electronic structures of the nanotubes. Our results have shed new light on the controlled synthesis and property-tuning of nano peapods.
... The adjustable electrical properties of these nanopeapods make them suitable for nanoelectronic applications. [2][3][4][5][6]. The structural and electronic properties of the whole set of endohedral metallofullerenes Zn m @C 60 and Zn m @C 70 (m = 1-5) as candidates for use in electronic devices, gas sensors and solar cells were obtained using DFT calculations [7]. ...
... Notably, the SWNTs possess prominent capillarity and have been used to grow and encapsulate diverse guests with appropriate diameters, providing an effective shield from the external environment. [16][17][18][19][20] The shape and size of many (sub)nanoscale POMs are well-matched with the inner diameter of SWNTs, and thus can be confined in their internal cavities to prevent the loss of active components. [21,22] Recently, Newton's group developed an efficient approach to encapsulate POMs (PW 12 , PMo 12 , P 2 Mo 18 ) in SWNTs, and unveiled that the mechanism of this process was driven by the charge transfer effect. ...
The host–guest interaction can remarkably alter the physiochemical properties of composite materials. It is crucial to clarify the mechanism by revealing the influence of the host on the electronic structure of the guest molecules. Herein, we study the structural variation of polyoxometalates (POMs) after being confined in single‐walled carbon nanotubes (SWNT). What we found is that in addition to the reported charge transfer from SWNT to POM, an intramolecular electron transfer within a single POM cluster can be observed in the POM@SWNT composites. Moreover, the charge density on the bridged oxygen of POMs is prominently enhanced. The structural change and electron reconfiguration of POMs upon encapsulation in SWNT significantly speed up electron and ion transport, leading to the improved electrochemical performance for sodium ions storage.
... The parchment in which the graphene sheet is rolled around itself as a rolled newspaper and the second model called the Russian Doll in which the arrangement of the graphite sheets is in the form of concentric cylinders concentric cylinders [12]. Other carbon nanotubes with their unique structures and applications mentioned in some articles and papers include graphenated CNTs [13][14], extreme CNTs [15][16][17], torus [18][19], nanobud [17], peapod [20][21], and cupstacked CNTs [22][23] Fig. 1. ...
The use of carbon nanotubes in a wide range of academic and industrial fields has received considerable attention due to their uniqueness in structures and properties. Despite these advantages, there are still some significant challenges and drawbacks such as insolubility which can have negative impacts on the application process. The introduction of functional groups on the surface of carbon nanotube can overcome this obstacle. Plasma functionalization can be a preferred method in comparison to other ones as a quick and relatively non-destructive, as well as environmentally-friendly method for the surface functionalization of carbon nanotubes. This review presents a brief introduction to the types, properties, and functionalization methods of carbon nanotubes for a better understanding. The focus of this review is on the modification of carbon nanotubes through different types of plasma functionalization methods, notably plasmas that operate at an ambient temperature and atmospheric pressure, to improve their properties. It also investigates the results obtained from analytical methods for plasma treated carbon nanotubes.
... It has been shown that filling of SWCNTs is a promising method for tailoring nanotube's optical and electrical properties due ease of doping protocols and presence of large varieties of dopants. Filling SWCNTs with C 60 fullerene and metallofullerene molecules, so called peapods, modifies the band gap of the nanotubes [20,21]. Replacing C 60 with Gd@C 82 metallofullerene molecules changed the properties of SWCNTs field-effect transistor from unipolar p-type to ambipolar character [22]. ...
We present transmission measurements on chirality enriched semiconducting (12,1) and (13,2) single-walled carbon nanotubes (CE-s-SWCNTs) and CE-s-SWCNTs doped with iodine (I2@CE-s-SWCNTs) and bromine (Br2@CE-s-SWCNTs) in wide frequency range from 0.1-40 THz. The real part of the optical conductivity σreal(ω) was fitted using Drude-Lorentz model. The Drude (D) term in the CE-s-SWCNTs was attributed to the presence of metallic tubes traces in the sample. The D/scattering rate(γD) ratio was increased by a factor of 1.13 and 2.35 with iodine and bromine p-doping, respectively. This increase was compensated by large increase in D term leading to an increase in the optical conductivity at the DC limit (σDC), growing from 186 Ω−1cm−1 for the CE-s-SWCNTs to 203 and 426 Ω−1cm−1 for the I2@CE-s-SWCNTs and Br2@CE-s-SWCNTs, respectively. In addition, the plasmon peak was shifted to higher frequencies and gains more spectral weight with doping. The calculated optical parameters determine that iodine and bromine create acceptor levels above the top of the CE-s-SWCNTs valence band by 0.04 and 0.08 eV, respectively, shifting the Fermi level. The high σDC value of the Br2@CE-s-SWCNTs is due to the higher electronegativity of bromine which enables removal of more electrons from the valence band of CE-s-SWCNTs to bromine acceptor levels.
... Introduction C 60 molecule, as a prototypical fullerene molecule, has attracted widespread attention due to its potential in endohedral fullerenes, 1 photovoltaic devices, 2 peapod nanotubes, 3 and singlemolecule transistors. 4 A C 60 monolayer grown on solid surfaces is critical for understanding and controlling the interfacial properties of fullerene-derived electronic and photovoltaic devices. ...
The interfacial structures of C60 molecules adsorbed on solid surfaces are essential for a wide range of scientific and technological processes in carbon-based nanodevices. Here, we report structural transitions of the C60 monolayer on the Bi(111) surface studied via low-temperature scanning tunneling microscopy (STM). With an increase in temperature, the structure of the C60 monolayer transforms from local-order structures to a (√93 × √93) R20° superstructure, and then to a (11 × 11) R0° superstructure. Moreover, the individual C60 molecules in different superstructures have different orientations. C60 molecules adopt the 6 : 6 C-C bond and 5 : 6 C-C bond facing-up, mixed orientations, and hexagon facing-up in the local-order structure, (√93 × √93) R20°, and (11 × 11) R0° superstructure, respectively. These results shed important light on the growth mechanism of C60 molecules on solid surfaces.
... Total energy electronic structure calculations [6] indicate that the encapsulating process for C 60 molecules into a ð10; 10Þ SWCNT is exothermic, which means that the resulting C 60 @ð10; 10Þ CNP is thermally stable. Strong modulation of electronic [7,8] and optical [9,12] properties of SWCNTs by fullerene encapsulation has been demonstrated. ...
Single-walled carbon nanotubes (SWCNTs) in their pristine form have high thermal conductivity whose further improvement has attracted a lot of interest. Some theoretical studies have suggested that the thermal conductivity of a $(10,10)$ SWCNT is dramatically enhanced by C$_{60}$ fullerene encapsulation. However, recent experiments on SWCNT bundles show that fullerene encapsulation leads to a reduction rather than an increase in thermal conductivity. Here, we employ three different molecular dynamics methods to study the influence of C$_{60}$ encapsulation on heat transport in a $(10,10)$ SWCNT. All the three methods consistently predict a reduction of the thermal conductivity of $(10,10)$ SWCNT upon C$_{60}$ encapsulation by $20\%-30\%$, in agreement with experimental results on bundles of SWCNTs. We demonstrate that there is a simulation artifact in the Green-Kubo method which gives anomalously large thermal conductivity from artificial convection. Our results show that the C$_{60}$ molecules conduct little heat compared to the outer SWCNT and reduce the phonon mean free paths of the SWCNT by inducing extra phonon scattering. We also find that the thermal conductivity of a $(10,10)$ SWCNT monotonically decreases with increasing filling ratio of C$_{60}$ molecules.
... Single-walled carbon nanotubes (SWCNTs) [1,2] are hollow structures which allows encapsulation of various molecules in them. A good example is C 60 fullerene [3] insertion into a SWCNT forming the so-called carbon nanopeapod (CNP) [4][5][6][7][8][9][10][11][12][13], where the nanotube acts as a pod and the encapsulated C 60 molecules act as peas. Total energy electronic structure calculations [6] indicate that the encapsulating process for C 60 molecules into a (10, 10) SWCNT is exothermic, which means that the resulting C 60 @(10, 10) CNP is thermally stable. ...
... Total energy electronic structure calculations [6] indicate that the encapsulating process for C 60 molecules into a (10, 10) SWCNT is exothermic, which means that the resulting C 60 @(10, 10) CNP is thermally stable. Strong modulation of electronic [7,8] and optical [9,12] properties of SWCNTs by fullerene encapsulation has been demonstrated. ...
... It provides a unique opportunity to investigate the structures and properties of 1D host-guest hybrid materials. [17][18][19][20][21][22][23] The intermolecular interactions in these self-assembled carbon nanostructures and the dynamic behavior of the encapsulated molecules [24] are different from those in solid fullerenes. [25][26][27] Thus studying the rotation dynamics of C 60 molecules under the 1D confined condition has attracted considerable interest recently. ...
... A notable application of CNT channels is the uptake and confinement of small molecule guests into 1D channels. [35][36][37] Thus, we were curious if the nanotube-like channels formed by fluorinated nanohoops are accessible to guests. As an initial approach, we sought to leverage the size and shape complementarity of fluorinated nanohoop 2, a [10]CPP derivative, with C60. ...
The scalable production of homogenous, uniform carbon nanomaterials represents a key synthetic challenge for contemporary organic synthesis as nearly all current fabrication methods provide heterogenous mixtures of various carbonized products. For carbon nanotubes (CNTs) in particular, the inability to access structures with specific diameters or chiralities severely limits their potential applications. Here, we present a general approach to access solid-state CNT mimic structures via the self-assembly of fluorinated nanohoops, which can be synthesized in a scalable, size-selective fashion. X-ray crystallography reveals that these CNT mimics exhibit uniform channel diameters that are precisely defined by the diameter of their nanohoop constituents, which self-assemble in a tubular fashion via a combination of arene-pefluoroarene and C—H---F interactions. The nanotube-like assembly of these systems results in capabilities such as linear guest alignment and permanently accessible channels, both of which are observed in CNTs but not in the analogous all-hydrocarbon nanohoop systems. Calculations suggest that the organofluorine interactions observed in the crystal structure are indeed critical in the self-assembly and robustness of the CNT mimic systems. This work establishes the self-assembly of carbon nanohoops via weak interactions as an attractive means to generate solid-state materials that mimic carbon nanotubes, importantly with the unparalleled tunability enabled by organic synthesis. <br
