Showing papers on "Fullerene published in 2015"
TL;DR: At Atomic-scale characterization, supported by theoretical calculations, revealed structures reminiscent of fused boron clusters with multiple scales of anisotropic, out-of-plane buckling that are consistent with predictions of a highly an isotropic, 2D metal.
Abstract: At the atomic-cluster scale, pure boron is markedly similar to carbon, forming simple planar molecules and cage-like fullerenes. Theoretical studies predict that two-dimensional (2D) boron sheets will adopt an atomic configuration similar to that of boron atomic clusters. We synthesized atomically thin, crystalline 2D boron sheets (i.e., borophene) on silver surfaces under ultrahigh-vacuum conditions. Atomic-scale characterization, supported by theoretical calculations, revealed structures reminiscent of fused boron clusters with multiple scales of anisotropic, out-of-plane buckling. Unlike bulk boron allotropes, borophene shows metallic characteristics that are consistent with predictions of a highly anisotropic, 2D metal.
1,873 citations
TL;DR: Applications of Fullerenes, Carbon Dots, Nanotubes, Graphene, Nanodiamonds, and Combined Superstructures.
Abstract: and Applications of Fullerenes, Carbon Dots, Nanotubes, Graphene, Nanodiamonds, and Combined Superstructures Vasilios Georgakilas,† Jason A. Perman,‡ Jiri Tucek,‡ and Radek Zboril*,‡ †Material Science Department, University of Patras, 26504 Rio Patras, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 listopadu 1192/12, 771 46 Olomouc, Czech Republic
1,366 citations
TL;DR: The motivation to replace fullerene acceptors stems from their synthetic inflexibility, leading to constraints in manipulating frontier energy levels, as well as poor absorption in the solar spectrum range, and an inherent tendency to undergo postfabrication crystallization, resulting in device instability.
Abstract: ConspectusThe active layer in a solution processed organic photovoltaic device comprises a light absorbing electron donor semiconductor, typically a polymer, and an electron accepting fullerene acceptor. Although there has been huge effort targeted to optimize the absorbing, energetic, and transport properties of the donor material, fullerenes remain as the exclusive electron acceptor in all high performance devices. Very recently, some new non-fullerene acceptors have been demonstrated to outperform fullerenes in comparative devices. This Account describes this progress, discussing molecular design considerations and the structure–property relationships that are emerging.The motivation to replace fullerene acceptors stems from their synthetic inflexibility, leading to constraints in manipulating frontier energy levels, as well as poor absorption in the solar spectrum range, and an inherent tendency to undergo postfabrication crystallization, resulting in device instability. New acceptors have to address ...
1,026 citations
TL;DR: Close- packed bundles of subnanometre-diameter sp(3)-bonded carbon threads capped with hydrogen, crystalline in two dimensions and short-range ordered in the third promise extraordinary properties such as strength and stiffness higher than that of sp(2) carbon nanotubes or conventional high-strength polymers.
Abstract: Low-dimensional carbon nanomaterials such as fullerenes, nanotubes, graphene and diamondoids have extraordinary physical and chemical properties. Compression-induced polymerization of aromatic molecules could provide a viable synthetic route to ordered carbon nanomaterials, but despite almost a century of study this approach has produced only amorphous products. Here we report recovery to ambient pressure of macroscopic quantities of a crystalline one- dimensional sp(3) carbon nanomaterial formed by high-pressure solid-state reaction of benzene. X-ray and neutron diffraction, Raman spectroscopy, solid-state NMR, transmission electron microscopy and first-principles calculations reveal close- packed bundles of subnanometre-diameter sp(3)-bonded carbon threads capped with hydrogen, crystalline in two dimensions and short-range ordered in the third. These nanothreads promise extraordinary properties such as strength and stiffness higher than that of sp(2) carbon nanotubes or conventional high-strength polymers. They may be the first member of a new class of ordered sp(3) nanomaterials synthesized by kinetic control of high-pressure solid-state reactions.
255 citations
TL;DR: The development of a ReaxFF reactive potential that can accurately describe the chemistry and dynamics of carbon condensed phases and the results obtained on fullerene fragmentation provide an important step toward the full computational chemical modeling of coal pyrolysis, soot incandescence, high temperature erosion of graphitic rocket nozzles, and ablation of carbon-based spacecraft materials during atmospheric reentry.
Abstract: In this article, we report the development of a ReaxFF reactive potential that can accurately describe the chemistry and dynamics of carbon condensed phases. Density functional theory (DFT)-based calculations were performed to obtain the equation of state for graphite and diamond and the formation energies of defects in graphene and amorphous phases from fullerenes. The DFT data were used to reparametrize ReaxFFCHO, resulting in a new potential called ReaxFFC-2013. ReaxFFC-2013 accurately predicts the atomization energy of graphite and closely reproduces the DFT-based energy difference between graphite and diamond, and the barrier for transition from graphite to diamond. ReaxFFC-2013 also accurately predicts the DFT-based energy barrier for Stone–Wales transformation in a C60(Ih) fullerene through the concerted rotation of a C2 unit. Later, MD simulations of a C180 fullerene using ReaxFFC-2013 suggested that the thermal fragmentation of these giant fullerenes is an exponential function of time. An Arrheni...
251 citations
TL;DR: This tutorial review provides a short introduction to carbon nanostructures, and shows the basic concepts of π-π interactions involving fullerenes, carbon nanotubes, and graphene.
Abstract: π–π Interactions are the dominating supramolecular forces in systems like carbon nanostructures, which are inherently constituted by large conjugated π-systems. Their skilful use has allowed the construction of fascinating supramolecular ensembles, thus opening a new avenue in carbon chemistry. In this tutorial review, we provide a short introduction to carbon nanostructures, and show the basic concepts of π–π interactions involving fullerenes, carbon nanotubes, and graphene.
238 citations
TL;DR: Fullerene C60 is used as starting material, due to its well-defined dimension, to produce very small graphene quantum dots (∼2-3 nm), which exhibited strong luminescence properties, with the highest intensity at 460 nm under a 340 nm excitation wavelength.
Abstract: Graphene quantum dots is a class of graphene nanomaterials with exceptional luminescence properties. Precise dimension control of graphene quantum dots produced by chemical synthesis methods is currently difficult to achieve and usually provides a range of sizes from 3 to 25 nm. In this work, fullerene C60 is used as starting material, due to its well-defined dimension, to produce very small graphene quantum dots (∼2–3 nm). Treatment of fullerene C60 with a mixture of strong acid and chemical oxidant induced the oxidation, cage-opening, and fragmentation processes of fullerene C60. The synthesized quantum dots were characterized and supported by LDI-TOF MS, TEM, XRD, XPS, AFM, STM, FTIR, DLS, Raman spectroscopy, and luminescence analyses. The quantum dots remained fully dispersed in aqueous suspension and exhibited strong luminescence properties, with the highest intensity at 460 nm under a 340 nm excitation wavelength. Further chemical treatments with hydrazine hydrate and hydroxylamine resulted in red- ...
229 citations
TL;DR: In this article, the authors report a novel route for bulk production of record long acetylenic linear carbon chains protected by thin double-walled carbon nanotubes, which is unambiguously confirmed by transmission electron microscopy and near-field Raman spectroscopy.
Abstract: The extreme instability and strong chemical activity of carbyne, the infinite sp1 hybridized carbon chain, are responsible for its low possibility to survive in ambient conditions. Therefore, much less has been possible to explore about carbyne as compared to other novel carbon allotropes such as fullerenes, nanotubes and graphene. Although end-capping groups can be used to stabilize carbon chains, length limitation is still a barrier for its actual production, and even more for applications. Here, we report a novel route for bulk production of record long acetylenic linear carbon chains protected by thin double-walled carbon nanotubes. A corresponding extremely high Raman band is the first proof of a truly bulk yield formation of very long arrangements, which is unambiguously confirmed by transmission electron microscopy and near-field Raman spectroscopy. Our production establishes a way to exceptionally long stable carbon chains including more than 2300 carbon atoms, and an elegant forerunner towards the final goal of a bulk production of essentially infinite carbyne.
205 citations
TL;DR: Graphene nanosheets will challenge the current existing adsorbents, including other types of carbon-based nanomaterials, to remove low concentrated contaminants from aqueous solutions.
200 citations
TL;DR: In this article, the authors reported the first demonstration of orthorhombic CsSnI3 films prepared from solution at room temperature that have defect densities low enough for use as the light harvesting semiconductor in photovoltaic devices even without using excess SnI2 in the preparative method.
Abstract: We report the first demonstration of orthorhombic CsSnI3 films prepared from solution at room temperature that have defect densities low enough for use as the light harvesting semiconductor in photovoltaic devices even without using excess Sn in the preparative method, and demonstrate their utility in a model p–i–n photovoltaic device based on a CuI | CsSnI3 | fullerene planar layer architecture. We also report an effective strategy for simultaneously improving both the efficiency and stability of these devices towards air exposure based on the use of excess of SnI2 during CsSnI3 synthesis from CsI and SnI2. A combination of photoelectron spectroscopy, contact potential measurements and device based studies are used to elucidate the basis for this improvement and role of the excess SnI2. The open-circuit voltage in these lead-free photovoltaic devices is shown to be strongly dependent on the degree of alignment between the perovskite conduction band edge and the lowest occupied molecular orbital (LUMO) in the fullerene electron transport layer. Furthermore, the energetics at the perovskite–fullerene interface are shown to be a function both of the LUMO energy of the fullerene and the nature of the interaction at the heterojunction which can give rise to a large abrupt vacuum level shift across the interface. A champion open-circuit voltage of ∼0.55 V is achieved using indene-C60 bis-adduct as the electron extraction layer, which is twice that previously reported for a CsSnI3 based PPV.
167 citations
TL;DR: It is established that the combination of gold and alcohol is crucial to carbyne formation because carbon-hydrogen bonds can be cleaved with the help of gold catalysts under the favorable thermodynamic environment provided by laser ablation in liquid.
Abstract: Carbyne is the one-dimensional allotrope of carbon composed of sp-hybridized carbon atoms. Definitive evidence for carbyne has remained elusive despite its synthesis and preparation in the laboratory. Given the remarkable technological breakthroughs offered by other allotropes of carbon, including diamond, graphite, fullerenes, carbon nanotubes, and graphene, interest in carbyne and its unusual potential properties remains intense. We report the first synthesis of carbyne with finite length, which is clearly composed of alternating single bonds and triple bonds, using a novel process involving laser ablation in liquid. Spectroscopic analyses confirm that the product is the structure of sp hybridization with alternating carbon-carbon single bonds and triple bonds and capped by hydrogen. We observe purple-blue fluorescence emissions from the gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital of carbyne. Condensed-phase carbyne crystals have a hexagonal lattice and resemble the white crystalline powder produced by drying a carbyne solution. We also establish that the combination of gold and alcohol is crucial to carbyne formation because carbon-hydrogen bonds can be cleaved with the help of gold catalysts under the favorable thermodynamic environment provided by laser ablation in liquid and because the unique configuration of two carbon atoms in an alcohol molecule matches the elementary entity of carbyne. This laboratory synthesis of carbyne will enable the exploration of its properties and applications.
TL;DR: In this paper, a comparative study of the stability of polymer/fullerene bilayers using two common OPV polymer donors poly(3-hexylthiophene), P3HT, and poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)], PCDTBT, and four fullerene acceptors phenyl-C61
Abstract: A consensus is emerging that mixed phases are present in bulk heterojunction organic photovoltaic (OPV) devices. Significant insights into the mixed phases have come from bilayer stability measurements, in which an initial sample consisting of material pure layers of donor and acceptor is thermally treated, resulting in swelling of one layer by the other. We present a comparative study of the stability of polymer/fullerene bilayers using two common OPV polymer donors poly(3-hexylthiophene), P3HT, and poly[N-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)], PCDTBT, and four fullerene acceptors phenyl-C61-butyric acid methyl ester, phenyl-C71-butyric acid methyl ester, [60]PCBM bis-adduct, and indene C60 bis-adduct. Using in situ spectroscopic ellipsometry to characterize the quasi-steady state behavior of the films, we find that the polymer glass transition temperature (Tg) is critical to the bilayer stability, with no significant changes occurring below Tg of the high ...
TL;DR: By reviewing the major types of multi functionalized fullerenes through selected examples with a link to the structural assignments, the authors intend to give a concise overview to the specialist in the field and to provide the non-specialist with a tool box of possibilities.
Abstract: Highly functionalized fullerenes can be efficiently constructed by various techniques. However, the challenge is to synthesize highly symmetrical fullerenes. Recently, a number of X-ray structures have been disclosed showing the high symmetry of substituted fullerenes. By reviewing the major types of multi functionalized fullerenes through selected examples with a link to the structural assignments, the authors intend to give a concise overview to the specialist in the field and to provide the non-specialist with a tool box of possibilities.
TL;DR: The thermal conversion of one-dimensional (1D) fullerene (C60) single-crystal nanorods and nanotubes to nanoporous carbon materials with retention of the initial 1D morphology yields a new family of nanoporous carbons having π-electron conjugation within the sp(2)-carbon robust frameworks.
Abstract: Here we report the thermal conversion of one-dimensional (1D) fullerene (C-60) single-crystal nanorods and nanotubes to nanoporous carbon materials with retention of the initial 1D morphology The 1D C-60 crystals are heated directly at very high temperature (up to 2000 degrees C) in vacuum, yielding a new family of nanoporous carbons having pi-electron conjugation within the sp(2)-carbon robust frameworks These new nanoporous carbon materials show excellent electrochemical capacitance and superior sensing properties for aromatic compounds compared to commercial activated carbons
TL;DR: Two degree based topological indices, the atom-bond connectivity (ABC) and the geometric-arithmetic (GA) indices of fullerene networks and carbon nanotube networks are studied.
TL;DR: Novel quantitative predictions of the energy and stability of fullerene molecules are reported, the very first attempt in using persistent homology in this context.
Abstract: Persistent homology is a relatively new tool often used for qualitative analysis of intrinsic topological features in images and data originated from scientific and engineering applications. In this article, we report novel quantitative predictions of the energy and stability of fullerene molecules, the very first attempt in using persistent homology in this context. The ground-state structures of a series of small fullerene molecules are first investigated with the standard Vietoris-Rips complex. We decipher all the barcodes, including both short-lived local bars and long-lived global bars arising from topological invariants, and associate them with fullerene structural details. Using accumulated bar lengths, we build quantitative models to correlate local and global Betti-2 bars, respectively with the heat of formation and total curvature energies of fullerenes. It is found that the heat of formation energy is related to the local hexagonal cavities of small fullerenes, while the total curvature energies of fullerene isomers are associated with their sphericities, which are measured by the lengths of their long-lived Betti-2 bars. Excellent correlation coefficients (>0.94) between persistent homology predictions and those of quantum or curvature analysis have been observed. A correlation matrix based filtration is introduced to further verify our findings.
TL;DR: This work investigates the binding ability and hydrogen storage capacity of Ti-decorated B40 fullerene based on DFT calculations and indicates that Ti shows excellent binding capability to B40 compared with other transition metals.
Abstract: The newly found B40 is the first experimentally observed all-boron fullerene and has potential applications in hydrogen storage. Here we investigate the binding ability and hydrogen storage capacity of Ti-decorated B40 fullerene based on DFT calculations. Our results indicate that Ti shows excellent binding capability to B40 compared with other transition metals. The B40 fullerene coated by 6 Ti atoms (Ti6B40) can store up to 34 H2 molecules, corresponding to a maximum gravimetric density of 8.7 wt%. It takes 0.2-0.4 eV/H2 to add one H2 molecule, which assures reversible storage of H2 molecules under ambient conditions. The evaluated reversible storage capacity is 6.1 wt%. Our results demonstrate that the new Ti-decorated B40 fullerene is a promising hydrogen storage material with high capacity.
TL;DR: In this paper, the structural organization of C60 fullerenes in aqueous solution was studied and analyzed in detail using various techniques such as chemical analysis, UV/VIS spectroscopy, atomic force and scanning tunneling microscopy, dynamic light scattering, and zeta potential methods.
Abstract: The method of preparation of highly stable reproducible C60 fullerene aqueous colloid solution is described. The structural organization of C60 fullerenes in aqueous solution was studied and analyzed in detail using various techniques such as chemical analysis, UV/VIS spectroscopy, atomic force and scanning tunneling microscopy, dynamic light scattering, and zeta potential methods.
TL;DR: In this paper, an alternative processing route is investigated in which the two active layer components are deposited sequentially via spin coating or doctor blading, and the influence of the second-layer solvent for the fullerene derivative is investigated.
Abstract: Polymer solar cells are conventionally processed by coating a multicomponent mixture containing polymer, fullerene, solvent, and cosolvent. The photovoltaic performance strongly depends on the nanoscale morphology of the blend, which is largely determined by the precise nature of the solvent composition and drying conditions. Here, an alternative processing route is investigated in which the two active layer components are deposited sequentially via spin coating or doctor blading. Spin coating the fullerene from o-dichlorobenzene on top of the polymer provides virtually identical morphologies and photovoltaic performance. Using blade coating, the influence of the second-layer solvent for the fullerene derivative is investigated in further detail. Different aromatic solvents are compared regarding swelling of the polymer layer, fullerene solubility, and evaporation rate. It is found that while swelling of the polymer by the second-layer solvent is a necessity for sequential processing, the solubility of the fullerene derivative in this solvent has the strongest influence on solar cell performance. Homogeneous layers in which a sufficient amount of fullerene can infiltrate the polymer film can only be achieved when solvents are used that have a very high solubility for the fullerene and swell the polymer layer.
TL;DR: The analytical method was applied in order to assess the occurrence of selected fullerenes in 45 soils of Sul Catarinense (Santa Catalina State, Brazil) and 15 sediments from the Tubarão River, presenting different pressures of contamination.
TL;DR: This paper reviews recent FNWs research focusing on their mechanical, electrical and superconducting properties and growth mechanisms in the liquid–liquid interfacial precipitation method.
TL;DR: A brand new approach to achieve high-efficiency metal-free growth of nearly pure SWCNT semiconductors, as supported by extensive spectroscopic characterization, electrical transport measurements, and density functional theory calculations is reported.
Abstract: The inability to synthesize single-wall carbon nanotubes (SWCNTs) possessing uniform electronic properties and chirality represents the major impediment to their widespread applications. Recently, there is growing interest to explore and synthesize well-defined carbon nanostructures, including fullerenes, short nanotubes, and sidewalls of nanotubes, aiming for controlled synthesis of SWCNTs. One noticeable advantage of such processes is that no metal catalysts are used, and the produced nanotubes will be free of metal contamination. Many of these methods, however, suffer shortcomings of either low yield or poor controllability of nanotube uniformity. Here, we report a brand new approach to achieve high-efficiency metal-free growth of nearly pure SWCNT semiconductors, as supported by extensive spectroscopic characterization, electrical transport measurements, and density functional theory calculations. Our strategy combines bottom-up organic chemistry synthesis with vapor phase epitaxy elongation. We ident...
TL;DR: The structural stability and physicochemical properties of the N-rich BN fullerene, B24N36, have been analyzed by means of the density functional theory at the level of the generalized gradient approximation as discussed by the authors.
Abstract: The structural stability and physicochemical properties of the N-rich BN fullerene, B24N36, have been analyzed by means of the density functional theory at the level of the generalized gradient approximation For this purpose, the Heyd–Scuseria–Ernzerhof (HSE) screened hybrid density functional and the 6-31G(d) basis set were used The results indicate that the B24N36 fullerene is stable and behaves as a semiconductor compound It has been found that while the polarity of the B24N36 fullerene is comparable with that of C60 fullerene, its chemical reactivity is notoriously higher The spatial charge distribution of the BN fullerene allows nitric oxide adsorption, without compromising structural stability Although the interaction between the NO molecule and BN fullerene is through van der Waals forces (dipole–dipole attraction), it has strong influence on the dipole moment, vibrational modes, HOMO–LUMO gap and work function energy; suggesting that this nanostructure could be used as a molecular sensor or drug carrier with enhanced bioavailability
TL;DR: Using an electro-absorption (Stark effect) signature, the migration of holes from intermixed to neat regions is directly visualize, which occurs on the subpicosecond time scale and is likely sustained by high local mobility and by an energy cascade driving the holes toward the neat domains.
Abstract: We reveal some of the key mechanisms during charge generation in polymer:fullerene blends exploiting our well-defined understanding of the microstructures obtained in pBTTT:PCBM systems via processing with fatty acid methyl ester additives. Based on ultrafast transient absorption, electro-absorption, and fluorescence up-conversion spectroscopy, we find that exciton diffusion through relatively phase-pure polymer or fullerene domains limits the rate of electron and hole transfer, while prompt charge separation occurs in regions where the polymer and fullerene are molecularly intermixed (such as the co-crystal phase where fullerenes intercalate between polymer chains in pBTTT:PCBM). We moreover confirm the importance of neat domains, which are essential to prevent geminate recombination of bound electron–hole pairs. Most interestingly, using an electro-absorption (Stark effect) signature, we directly visualize the migration of holes from intermixed to neat regions, which occurs on the subpicosecond time sca...
TL;DR: The demonstration of one-dimensional electron confinement in graphene provides the novel possibility of controlling its electronic properties not by chemical modification but by ‘mechanical structuring'.
Abstract: Graphene-based carbon materials such as fullerenes, carbon nanotubes, and graphenes have distinct and unique electronic properties that depend on their dimensionality and geometric structures. Graphene wrinkles with pseudo one-dimensional structures have been observed in a graphene sheet. However, their one-dimensional electronic properties have never been observed because of their large widths. Here we report the unique electronic structure of graphene nanowrinkles in a graphene sheet grown on Ni(111), the width of which was small enough to cause one-dimensional electron confinement. Use of spatially resolved, scanning tunnelling spectroscopy revealed bandgap opening and a one-dimensional van Hove singularity in the graphene nanowrinkles, as well as the chemical potential distribution across the graphene nanowrinkles. This observation allows us to realize a metallic-semiconducting-metallic junction in a single graphene sheet. Our demonstration of one-dimensional electron confinement in graphene provides the novel possibility of controlling its electronic properties not by chemical modification but by ‘mechanical structuring'.
Journal Article•
TL;DR: This study points out the opportunity of predicting the electric dipole moment distribution on complex graphene-based nanostructures based only on the local curvature information, and establishes the universality of the linear dependence of flexoelectric atomic dipole moments on local curvatures in various carbon networks.
Abstract: We report theoretical analysis of the electronic flexoelectric effect associated with nanostructures of sp(2) carbon (curved graphene). Through the density functional theory calculations, we establish the universality of the linear dependence of flexoelectric atomic dipole moments on local curvature in various carbon networks (carbon nanotubes, fullerenes with high and low symmetry, and nanocones). The usefulness of such dependence is in the possibility to extend the analysis of any carbon systems with local deformations with respect to their electronic properties. This result is exemplified by exploring of flexoelectric effect in carbon nanocones that display large dipole moment, cumulative over their surface yet surprisingly scaling exactly linearly with the length, and with sine-law dependence on the apex angle, dflex ~ L sin(α). Our study points out the opportunity of predicting the electric dipole moment distribution on complex graphene-based nanostructures based only on the local curvature information.
TL;DR: It is shown that discrete Si20 dodecahedra, stabilized by an endohedral guest and valence saturation, are accessible in preparative yields through a chloride-induced disproportionation reaction of hexachlorodisilane in the presence of tri(n-butyl)amine.
Abstract: Silicon analogues of the most prominent carbon nanostructures, namely, hollow spheroidals such as C60 and the fullerene family, have been unknown to date Herein we show that discrete Si20 dodecahedra, stabilized by an endohedral guest and valence saturation, are accessible in preparative yields through a chloride-induced disproportionation reaction of hexachlorodisilane in the presence of tri(n-butyl)amine X-ray crystallography revealed that each silicon dodecahedron contains an endohedral chloride ion that imparts a net negative charge Eight chloro substituents and twelve trichlorosilyl groups are attached to the surface of each cluster in a strictly regioregular arrangement, a thermodynamically preferred substitution pattern according to quantum-chemical assessment Our results demonstrate that the wet-chemical self-assembly of a complex, monodisperse Si nanostructure is possible under mild conditions starting from simple Si2 building blocks
TL;DR: Stabilized fullerene and tubular forms can be produced in boron clusters Bn in small sizes from n∼ 14 to 20 upon doping by transition metal atoms and suggest the use of dopants to induce different growth paths leading to larger cages, fullerenes and tubes of borons.
Abstract: Stabilized fullerene and tubular forms can be produced in boron clusters Bn in small sizes from n ∼ 14 to 20 upon doping by transition metal atoms. B14Fe and B16Fe are stable tubes whereas B18Fe and B20Fe are stable fullerenes. Their formation and stability suggest the use of dopants to induce different growth paths leading to larger cages, fullerenes and tubes of boron.
TL;DR: Li et al. as mentioned in this paper used a facile solid-state mechanochemical method by ball milling to synthesize the first directly bonded graphene-C60 hybrid, for which LiOH was found to play a crucial role as the catalyst.
Abstract: Using a facile solid-state mechanochemical method by ball milling, we successfully synthesized the first directly bonded graphene–C60 hybrid, for which LiOH is found to play a crucial role as the catalyst. The hybrid structure of graphene–C60 is confirmed by FTIR, Raman, XRD and XPS characterizations, and its conformation is proposed, featuring the direct bonding of graphene nanoplatelets and C60via two C–C single bonds. SEM measurement suggests that severe edge distortions occur for graphene–C60 hybrid, and HR-TEM study indicate the covalent attaching of C60 molecules onto the edge of graphene nanoplatelets. The graphene–C60 hybrid is applied as a carbon-based electrocatalyst toward oxygen reduction reaction (ORR), showing improved ORR electrocatalytic activity than the pristine graphite.