Raman spectroscopy of polyhedral carbon nano-onions

Pujals, Daniel Codorniu; Fuentes, Olimpia Arias de; García, Luis Felipe Desdín; Cazzanelli, E.; Caputi, Lorenzo

doi:10.1007/s00339-015-9315-9

Cited by 30 publications

(11 citation statements)

References 24 publications

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“…A related, but separate question is whether any gyroscopic motion would be spectroscopically observable. Traditionally, Raman spectroscopy has been the method of choice for the investigation of CNOs, and the focus has been on distinguishing CNOs from other carbon nanostructures. − The experimental difficulties in producing pure carbon nano-onions (i.e., free from other carbon nanocompounds) with a well-defined monodispersity are often cited as reasons for the use of Raman spectroscopy over other methods …”

Section: Resultsmentioning

confidence: 99%

Carbon Nano-onions as Photosensitizers: Stacking-Induced Red-Shift

Hashmı

Lein

2018

J. Phys. Chem. C

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electronic structure calculations. We were able to show that earlier work, which showed the free rotation of the inner fullerene in a CNO, does not extend to multilayered CNOs. We show that the likely reason for this immobility of the outer layers is the superadditivity of the interaction energies between individual shells, i.e., the total interaction energy of all shells is larger than the sum of all individual interaction energies between pairs of shells. We also show how the electronic states of individual fullerenes are polarized but essentially preserved in CNOs and how charge-transfer excitations between layers arise, which are significantly red-shifted to lower absorption energies compared to those of the free fullerenes. This allows CNOs to be utilized as photosensitizers in nanotechnology applications.

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Section: Resultsmentioning

confidence: 99%

Carbon Nano-onions as Photosensitizers: Stacking-Induced Red-Shift

Hashmı

Lein

2018

J. Phys. Chem. C

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“…The mixture was later centrifuged for 10 min followed by collection of the black powder that formed in the bottom of the test tube. Then, Salzmann’s protocol was applied to purify the oxidized CNOs (CNOs ox ) [51]. The resulting oxidized product was stirred in 3.0 M of NaOH and washed several times with distilled water until a final pH of 7 was reached, and then dried overnight at 110 °C.…”

Section: Methodsmentioning

confidence: 99%

Nanoforest: Polyaniline Nanotubes Modified with Carbon Nano-Onions as a Nanocomposite Material for Easy-to-Miniaturize High-Performance Solid-State Supercapacitors

et al. 2018

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This article describes a facile low-cost synthesis of polyaniline nanotube (PANINT)–carbon nano-onion (CNO) composites for solid-state supercapacitors. Scanning electron microscopic (SEM) analyses indicate a uniform and ordered composition for the conducting polymer nanotubes immobilized on a thin gold film. The obtained nanocomposites exhibit a brush-like architecture with a specific capacitance of 946 F g−1 at a scan rate of 1 mV s−1. In addition, the nanocomposites offer high conductivity and a porous and well-developed surface area. The PANINT–CNO nanocomposites were tested as electrodes with high potential and long-term stability for use in easy-to-miniaturize high-performance supercapacitor devices.

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“…The D band’s intensity ratio to that of the G band was measured to be 1.08, indicating the poor graphitic nature of TPW. ,, On the other hand, in the case of OLCs, in addition to the D band at 1344 cm –1 and the G band at 1575 cm –1 , another prominent band, namely, the 2D band (overtone of D band) at 2684 cm –1 is observed. The 2D band’s appearance indicates the presence of graphene layers in OLC particles. − The slight asymmetry of the 2D band indicates that the OLC particles are constituted by multiple graphene layers, agreeing well with the HRTEM observations (Figure d). In the case of OLC, the D band’s intensity ratio to that of the G band was measured as 0.81, indicating enhanced graphitization attributed to the heat treatment. ,− …”

Section: Resultsmentioning

confidence: 97%

Sustainable Kilogram-Scale Conversion of Tire Pyrolysis Waste into Nanosized Onion-like Carbons with Extraordinary Lubricant-Additive Properties

Ravikiran,

Padya,

Junaid

et al. 2023

ACS Sustainable Chem. Eng.

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Tire pyrolysis waste (TPW) is converted into highly crystalline and nanosized onion-like carbons (OLCs) on a kilogram scale using an easy and controlled heat treatment. An OLC-dispersed additive-free group-II N500 base oil (BO) sample exhibited increased density, lower viscosity, and reduced internal fluid shear stress compared to BO. The nanoscale of OLC induced a change in the dispersing medium's conformation and free volume, resulting in a non-Einstein-like decrease of viscosity. When used as a lubricant in the four-ball wear test, the OLC-added BO sample caused nanoscale sliding and rolling effects at the points of contact, considerably reducing the coefficient of friction and wear. Surprisingly, TPW also showed similar behavior to OLC. Here, it is elucidated that OLC and TPW are anti-friction and anti-wear nanoadditives in lubricants that reduce friction and wear substantially. TPW could also be used as a low-cost additive in lubricants with no stringent restrictions on the presence of minor impurities and in several other applications. This is expected to ease the economics involved and facilitate the liberal use of OLC in various applications, as discussed in brief in this work.

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Raman spectroscopy of polyhedral carbon nano-onions

Cited by 30 publications

References 24 publications

Carbon Nano-onions as Photosensitizers: Stacking-Induced Red-Shift

Carbon Nano-onions as Photosensitizers: Stacking-Induced Red-Shift

Nanoforest: Polyaniline Nanotubes Modified with Carbon Nano-Onions as a Nanocomposite Material for Easy-to-Miniaturize High-Performance Solid-State Supercapacitors

Sustainable Kilogram-Scale Conversion of Tire Pyrolysis Waste into Nanosized Onion-like Carbons with Extraordinary Lubricant-Additive Properties

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