Multilayer Fullerenes Research Articles

Facile chemical vapor deposition (CVD) method for synthesis of high purity carbon nano-onions

Multi-layered fullerenes, known as “carbon nano-onions,” are attractive for various applications due to their shape, size, and surface area. A standard method usually uses powder catalysts, which require an additional step to separate and purify nano-onions after their synthesis. In this work, a simple method based on chemical vapor deposition and a copper foil as a catalyst has been developed. The effect of growth time on the structural, chemical, and morphological properties of nano-onions was investigated. The results indicate that carbon nano-onions with different degrees of graphitization, diameters, and thermal stability are obtained independently of the growth time.

Biodegradability of Carbon Nano‐Onions by Human Myeloperoxidase and Photo‐Fenton Process

The biodegradability of carbon nanomaterials (CNMs) in the environment and organisms needs to be understood, and it is highly essential to estimate their in vivo fate, especially for clinical applications. It is also important to investigate their metabolites formation to fully understand their biocompatibility. Herein, we explored the biodegradability of multilayer fullerenes, better known as carbon nano‐onions (CNOs), by treating them with human myeloperoxidase (hMPO) isolated from the neutrophils, plant enzyme horseradish peroxidase (HRP) and the photo‐Fenton (PF) reaction. High‐resolution electron microscopy (HRTEM), Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and mass spectrometry (MS) results confirmed that CNOs are not bio‐persistent. Moreover, these results indicate that the oxidized (functionalized) CNOs can undergo faster biodegradation than the pristine CNOs. The possible by‐products of biodegradation of CNOs were characterized using mass spectrometry. An understanding of the biodegradation properties of CNOs and their metabolites is fundamental for future biomedical applications.

Preparation of a new composite based on multilayer fullerene with mesoporous carbon nitride and its application in the extraction of tacrolimus and everolimus from plasma prior to LC-MS/MS analysis.

The development of new and efficient adsorbents for dispersive solid-phase extraction method, particularly prior to chromatography analysis, is increasing. In particular, this method is recommended for use before biological sample analysis. In this work, a new composite was prepared from mesoporous carbon nitrides and carbon nano-onions and was utilized for the extraction of tacrolimus and everolimus from plasma samples prior to high-performance liquid chromatography-tandem mass spectrometry analysis. To achieve this aim, first, mesoporous carbon nitrides and carbon nano-onions were synthesized separately and mixed at optimized proportions. Subsequently, a suitable amount of the prepared composite (5 mg) was added to 2 mL of sample solution containing the analytes under vortexing. Next, the extracted analytes were eluted using acetonitrile. The approach was linear within the ranges of 1.0-500 and 0.51-500 ng mL-1 for tacrolimus and everolimus, respectively. Sensitive limits of detection (0.31 and 0.15 ng mL-1 for tacrolimus and everolimus, respectively), acceptable relative standard deviations (intra- and inter-day precisions of ≤5.6% and high extraction recoveries of 71.0% and 83.0% for tacrolimus and everolimus, respectively) were obtained. The results showed that the method can be successfully applied in the simultaneous extraction of the studied analytes from plasma.

(Second Place Poster Award) Improving Oxygen Reduction Reaction ORR Fuel Cell Efficiency with Carbon Nano Onions

Hydrogen Fuel cell innovations are cutting-edge clean power solutions highly demanded nowadays. Since the oxygen reduction reaction (ORR) in fuel cells needs to be catalyzed heterogeneously, conductive substrates such as carbon materials are critical for the construction of electrocatalysts. Thus far, the research has been focused on commercially available carbon supports such as the well-known Vulcan, and the high-surface area Ketjenblack.[1] Thanks to the fast development of material science, other carbon supports such as graphite, graphene oxide, and carbon nanotubes have been also studied in a lesser extent, mainly due to their novelty and underdeveloped scale up syntheses.[2,3] This work focuses on utilizing a relatively new and, as of yet, largely unexplored carbon nanomaterial: carbon nano onions (CNOs).CNOs are spherical nanoparticles of about 5 nm diameter composed of concentrical multi-layered fullerenes, first discovered by Ugarte in 1992. CNOs exhibit outstanding properties such as low density, high thermal stability, and a graphitic multilayer morphology, which makes them excellent candidates for a wide variety of applications. Furthermore, the onion’s large surface area and high conductivity make them particularly interesting as catalyst support for electrochemical applications as they have already been demonstrated to be a superior Pt support alternative thanks to a higher cycling stability compared to carbon black, since their particle size and morphology suppress catalyst agglomeration and avoid its ripening.[4] However, despite their excellent long-term stability, the few available studies using CNOs were performed using the rotatory disc electrode (RDE) method, reaching only modest performance in the mA / cm2 range. Thus, our work aims to further extend upon this research by measuring the ORR performance with a gas diffusion electrode (GDE), to reproduce realistic fuel cell conditions.[5] The catalyst layer, obtained by growing Pt nanoparticles on CNOs, is characterized by electrochemical measurements such as ORR polarization curves, electrochemical active surface area (ECSA) by the CO-stripping method, and O2-mass transport. The utilization of GDE cells allows for higher current densities and a realistic catalyst mass transport compared to the RDE method, thus better representing an applied ORR fuel cell test.[6] [1] Electrochem. Solid-State Lett. 2005, 8, A320-A323[2] Carbon 2013, 58, 139-150[3] Energy Environ. Sci. 2010, 3, 1286-1293[4] ACS Appl. Mater. Interfaces 2017, 9, 28, 23302–23308[5] Angew. Chem. Int. Ed. 2021, 60, 8882-8888[6] ACS Energy Lett. 2022, 7, 2, 816–826 Figure 1

Synthesis of concentric multilayer fullerene nanostructures from mineral coal for applications in supercapacitors

Motivated by the need to find added value to Colombian mineral coal and explore its possible applications in energy storage systems, herein, carbon nano-onions (CNOs) structures were produced from mineral coal through thermal annealing under an inert atmosphere. Three coal samples were extracted from three distinct mines in Colombia, and thermal annealing was conducted on each sample at different times from 1 to 2 h, and temperatures between 1200 and 1600 °C. Through HR-TEM, it was possible to observe the formation of onion-like carbon structures with interlayer distances of 3.86 and 3.50 Å for annealing temperatures of 1600 and 1800 °C, respectively. On the other hand, cyclic voltammetry was carried out to evaluate the potential use of the materials in capacitive systems after undergoing heat treatment showing an increase of up to 5000 % in the specific capacitance of each sample concerning the original carbon. Additionally, the behavior of the charge storage process was analyzed by electrochemical impedance spectroscopy, where faradaic processes obtained the most significant contribution to the enhancement of the specific capacitance.

Molecular Dynamical Investigation of Lithium-Ion Adsorption on Multilayer Fullerene

As the cathode of lithium-ion batteries, carbon material has been the focus of research. At present, diverse investigations have been carried out on the lithium convergence behavior in the carbon material family. As a new carbon material, multilayer fullerenes have been shown in various experimental studies to have a high discharge rate as an electrode, indicating that onion-like carbon has the potential to release energy quickly. Materials and mechanical scientists are increasingly interested in lithium-ion batteries. In this paper, the molecular dynamics (MD) method was used to simulate the absorption of lithium ions by multilayer fullerenes. A model of five layers of fullerenes was established to compare the lithium-ion absorption rates of multiple layers of fullerenes at different lithium-ion concentrations. The effects of the lithium-ion diffusion rate on the results were considered. In addition, the effects of the number of lithium ions, the velocity, and the layer number of multilayer fullerenes on the structural behavior and stress were investigated thoroughly when the multilayer fullerenes adsorbed lithium ions.

Dynamics and structural transformations of carbon onion-like structures under high-velocity impacts

Carbon nano-onions (CNO) are multilayered fullerenes. They exhibit good electrical conductivity and large surface area, being of interest for several optoelectronic applications. However, it is still an open question what synthesis routes can be used to convert them into diamonds. Here, we used fully atomistic reactive (ReaxFF) molecular dynamics simulations to study the dynamics and structural transformations of CNO structures under high-velocity impacts against a fixed and rigid substrate. The aim of this study is to propose a new synthesis route, based on the mechanical impact of CNO, that can be exploited in the conversion of onions to diamonds. Our results indicated three regimes formed after the CNO impact: slightly deformed CNO (quasi-elastic collision, below 2.0 km/s), collapsed CNO (inelastic collisions, between 3.0 and 5.0 km/s) forming a diamondoid-like core, and fragmented CNO yielding linear atomic carbon chains (above 5.0 km/s). We also discussed the dynamical reconfiguration of carbon-carbon bonds during the collision process. The impact of CNO yielded sp3-like bond types for all the used initial velocities. At intermediate velocities (between 3.0 and 5.0 km/s), the inelastic collision forms diamondoid-like cores by converting a substantial quantity of sp2-like bonds into sp3-like ones.

Novel Gram‐Scale Synthesis of Carbon Nano‐Onions from Heavy Oil for Supercapacitors

AbstractCarbon nano‐onions (CNOs), recognized as multilayered fullerenes, display superior electrical conductivity (comparable with carbon black) and large surface area due to the highly defective sp2 carbon shells, making it a promising member of carbon nanomaterials for energy applications. However, the lack of efficient synthesis of CNOs in large‐scale production (gram quantities) has impeded their range of commercial applications. Herein, for the first time, it is demonstrated that the gram‐scale synthesis of CNOs is developed by simply annealing pitch‐coated petroleum coke for supercapacitors. Significantly, the CNOs with diameters of ≈5–30 nm and abundant micropores deliver outstanding specific capacitance of 312 F g−1 at 1 A g−1 and retain 251 F g−1 at 20 A g−1. Moreover, the corresponding synthesis mechanism is proposed to gain a clear insight into the formation of CNOs from heavy‐oil‐based carbon precursors. This work provides a practical pathway to synthesize CNOs on a large scale.

Fluorescent Carbon Nano-onion as Bioimaging Probe.

Concentrically arranged multilayered fullerenes exhibiting onion-like morphology are popularly known as carbon nano-onion (CNO) and are useful in bioimaging application. On the basis of the origin of the fluorescence, the CNO-based nanoprobes are classified into type I and type II. The type I CNO-based nanoprobe needs a secondary moiety such as organic dyes or an amine functionalization at its surface to induce the fluorescence. On the other hand, the emission in type II does not originate from such an external surface passivating agent. The CNO-based system not only shows structural similarity to the well-known multiwalled carbon nanotube but is also a bit more advantageous because of its low cytotoxicity. These features enable their prolonged use in the biological system for imaging purposes. In particular, we have covered the aspects of synthesis, surface functionalization, the origin of fluorescence, and biocompatibility. In addition, recent developments directed toward in vitro and in vivo imaging studies by utilizing CNO-based nanoprobes are summarized here.

Redox-additive electrolyte–driven enhancement of the electrochemical energy storage performance of asymmetric Co3O4//carbon nano-onions supercapacitors

For efficient energy storage, Co3O4@nickel foam exhibiting a plate-like (p-Co3O4) and grass-like (g-Co3O4) nanostructure were prepared as binder-free supercapacitor electrode materials. The electrochemical performance of the electrodes was tested using a redox-additive electrolyte (RAE). The homogeneously grown grass-like nanostructure (g-Co3O4) exhibited superior electrochemical performance to those with the plates-like structure (p-Co3O4) in a KOH electrolyte. In addition, the electrochemical performance of g-Co3O4 was improved using an RAE in a 3 M KOH solution. Remarkably, the specific capacitance of g-Co3O4 (1560 F g−1) was increased to 6580 F g−1, approximately 4-fold just by varying the RAE concentration in KOH. Carbon nano-onion (CNO) in the form of multi-layer fullerene was introduced as a negative electrode material. Owing to the more favorable morphology and properties of CNO such as exohedral structure, small diameter, high electrical conductivity, and relatively easy aqueous media dispersion than activated carbon and graphene, the as-fabricated asymmetric Co3O4//CNO supercapacitor delivered a high energy density of 42.5 Wh kg−1 and a high power density of 12.8 kW kg−1.

The Discovery of Few-Layered Graphene Flakes in Paragenetic Association with Other Carbon Nano-sized Mineral Phases

Interstitial fibrous-matted micron-scale aggregates of few-layered graphene nano-flakes, multi-layered carbon nanotubes, fullerenes, and fullerenoids have been found between quartz and potassium feldspar grains of slag-like high temperature and shock-metamorphosed rocks (polymictous sandstones) of the Dzharakuduk area (Kyzyl-Kum Desert, Uzbekistan). This is the first finding of few-layered graphene nano-flakes as well as multi-layered carbon nanotubes (with ~10 A inner diameters) and their assemblages as mineral component of natural rocks. Amount of layers in natural few-layered graphene nano-flakes varied from 19 to 45. Mechanisms of few-layered graphene nano-flakes generation in natural rocks are discussed.

Influence of Carbon Nanomodifier on the Structure and Properties of the Modified Gypsum Binder

Water-soluble polymer and latex additives are used to give the gypsum building plaster elasticity and placeability, improved water resistance and increased bending strength. The nanomodifiers in the form of carbon single-layer and multi-layer nanotubes, fullerenes and other nanoparticles are used for the formation of the structure of a gypsum stone with improved strength characteristics and improved weather resistance. In this work, the joint effect of the plasticizer based on polycarboxylate and the carbon nanomodifier on the structure, physicomechanical properties, and water resistance of the gypsum stone is investigated. It is shown that nanomodifiers contribute to the increase in the plasticizing ability of carboxylate additives, which leads to the significant decrease in the amount of mixing water, and as a result, to the increase in density, decrease in the porosity of the gypsum stone and the increase in its strength characteristics and water resistance.

Evidence of band gap features in Fe3O4 Bbmm filled carbon nano-onions

A key challenge in the fabrication of ferromagnetically filled multilayer fullerenes (carbon nano-onions, CNOs) is the manipulation of the structure, composition and electronic band characteristics of both the carbon layers and encapsulated ferromagnetic material. Interestingly, a recent work has demonstrated that the addition of small quantities of water during the chemical vapour synthesis of Fe3C filled CNOs can allow the local manipulation of the Fe3C crystal-structure and induce the nucleation of a novel high pressure Bbmm Fe3O4 crystal-phase. In this report we propose an advanced study of such structural transition. Particularly, we investigate the morphological, optical (band-gap) characteristics and magnetic properties of the as produced CNO materials by using transmission electron microscopy, vibrating sample magnetometry, x-ray photoelectron spectroscopy and UV–vis spectroscopy.

Сверхгидрофобное покрытие из углеродных наночастиц луковичной структуры

For the first time a superhydrophobic coating based on carbon nano-onions (multilayer fullerenes) synthesized through a cheap and technological method was obtained. Two simple and easily reproducible techniques of application were suggested. An opportunity of using the coating to control the composition and humidity of air was explored. Anti-icing properties were researched.

Novel 0D-nanocarbon-silica ceramic composites: sol-gel synthesis and high-temperature evolution.

Herein we report the synthesis of novel 0D-nanocarbon-based silicon-containing ceramic composites by a facile salt-free synthesis method followed by polymer-to-ceramic transformation. 0D-nanocarbon-silica composites were synthesized via a one-pot sol-gel process using tetramethyl orthosilicate (TMOS) and functionalized nanodiamonds and converted subsequently via pyrolysis under an argon atmosphere into nanodiamond/silica nanocomposites. The thermal conversion of the nanodiamond phase to a multilayer fullerene phase was carefully investigated by integral and local characterization methods such as vibrational spectroscopy, X-ray diffraction, BET, SEM and HRTEM. The incorporation of nanodiamonds in a silica matrix enhances the crystallization temperature of the silica phase, as α-cristobalite, to 1500 °C, while their full graphitization is shifted to T > 1700 °C under an argon atmosphere. The thermal decomposition of the nanodiamond/silica composites leads to the formation of materials with a high specific surface area (up to 562 m2 g-1) and a mesoporous structure. No carbothermal reaction of composing phases was identified. The results obtained in the present study allow for designing advanced and highly-defined mesoporous 0D-nanocarbon-containing composites with tailored structural features and multifunctional property profiles.

Preparation of Chitosan/Poly(Vinyl Alcohol) Nanocomposite Films Incorporated with Oxidized Carbon Nano-Onions (Multi-Layer Fullerenes) for Tissue-Engineering Applications.

Recently, tissue engineering became a very important medical alternative in patients who need to regenerate damaged or lost tissues through the use of scaffolds that support cell adhesion and proliferation. Carbon nanomaterials (carbon nanotubes, fullerenes, multi-wall fullerenes, and graphene) became a very important alternative to reinforce the mechanical, thermal, and antimicrobial properties of several biopolymers. In this work, five different formulations of chitosan/poly(vinyl alcohol)/oxidized carbon nano-onions (CS/PVA/ox-CNO) were used to prepare biodegradable scaffolds with potential biomedical applications. Film characterization consisted of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tension strength, Young’s modulus, X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The degradation in a simulated body fluid (FBS) demonstrated that all the formulations lost between 75% and 80% of their weight after 15 days of treatment, but the degradation decreased with the ox-CNO content. In vivo tests after 90 days of subdermal implantation of the nanocomposite films in Wistar rats’ tissue demonstrated good biocompatibility without allergenic reactions or pus formation. There was a good correlation between FBS hydrolytic degradation and degradation in vivo for all the samples, since the ox-CNO content increased the stability of the material. All these results indicate the potential of the CS/PVA/ox-CNO nanocomposite films in tissue engineering, especially for long-term applications.

Determination of the Hansen solubility parameters of carbon nano-onions and prediction of their dispersibility in organic solvents

Carbon nano-onions (CNOs) are the least studied allotropes of carbon despite their discovery before nanotubes and fullerenes. CNOs are multilayered fullerenes concentrically arranged one inside the other resembling the structure of an onion. Typically, their size average ranges from 2 to 50 nm in diameter. Recently, CNOs have gained attention in different fields because of their interesting chemical and physical properties. However, their lack of dispersibility in common solvents due to strong intermolecular interactions limits their applications. Here, we studied the dispersion behavior of CNOs prepared by nanodiamond annealing in 20 solvents of different polarities. Dynamic light scattering and transmission electron microscopy were used to study the dispersion of CNOs in the different solvents. The solvents were classified as “good” or “bad” solvents to determine the Hansen solubility parameters (HSP) of the CNOs using various optimization approaches. The calculated HSPs (δD, δP and δH) were further used to predict the CNO dispersion behavior in other solvents with a very good agreement between expected and observed dispersibilities. Our results will be helpful to estimate the behavior of CNOs in other solvents or their interaction with other materials with known HSPs.

Direct encapsulation of Sm single crystals inside carbon nano-onions by pyrolysis of Tris(tetramethylcyclopentadienyl) samarium (III)

Multilayer fullerenes (carbon nano-onions [CNOs]) have recently attracted important research interest because of their high chemical stability that allows the encapsulation of specific materials of interest and their protection from the external environment. Until now, CNOs have been filled with numerous crystals such as Sn, Pb Fe, Co, Ni, Cu, Fe3C, FePd3, Fe7C3, Fe5C2, FeCo, CoFe2O4, and others. However, to the best of our knowledge, no reports have yet shown the direct encapsulation of pure samarium (Sm) into these structures. The encapsulation of samarium within CNOs is expected to have an important impact toward applications of these systems in biomedicine and energy storage. In this work, we show a novel synthesis method that can allow the direct encapsulation of Sm single crystals inside CNOs. These structures are obtained by sublimation and pyrolysis of a not previously used hydrocarbon precursor, namely Tris(tetramethylcyclopentadienyl) samarium (III). The electrochemical performances of these structures are also demonstrated.

Carbon Nano-onions: A Valuable Class of Carbon Nanomaterials in Biomedicine.

The development of nanoscale materials is an important area of research as it provides access to materials with unique properties that can be applied to improve quality of life. Multi-layer fullerenes, also known as carbon nano-onions (CNOs) are an exciting class of nanostructures which show great versatility and applicability. They find applications in several fields of technology and biomedicine. This review highlights the potential advantages of CNOs for biomedical applications, which include but are not limited to bioimaging and sensing. Their good biocompatibility renders them promising platforms for the development of novel healthcare devices.

RuO2·nH2O Nanoparticles Anchored on Carbon Nano-onions: An Efficient Electrode for Solid State Flexible Electrochemical Supercapacitor

A flexible solid state electrochemical capacitor based on hydrous RuO2 nanoparticles, supported onto the nonporous and highly accessible ion adsorptive carbon nano-onions (CNOs), is fabricated in a novel process of modifying a conducting carbon paper to a flexible conducting substrate, separated with a poly(vinyl alcohol)/H2SO4 gel electrolyte. The sol–gel technique tends to form homogeneously dispersed RuO2 nanoparticles with the average size of ∼2.3 nm on the positive surface curvatures of multilayer fullerene (CNOs), which helps the high diffusivity of ions in both the aqueous and solid state gel electrolytes. The flexible substrate worked excellently as an electrical conductor as well as a stable mechanical support. This solid state flexible energy storage device showed a maximum energy density of 10.62 Whkg–1 and a maximum power density of 4.456 kWkg–1 for the hydrous RuO2/CNOs nanocomposite with 94.47% cycling stability even after 4000 cycles.