Creation of spherical carbon nanoparticles and clusters from carbon dioxide via UV dissociation at the critical point

Aschenbrenner, Ortrud; Fukuda, Toshio; Hasumura, Takashi; Maekawa, Toru; Cundy, Andrew B.; Whitby, Raymond L. D.

doi:10.1039/c2gc16593g

Cited by 3 publications

(4 citation statements)

References 39 publications

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“…Moreover, copper by itself is readily dissolved by 75 vol% D2EHPA without addition of other oxidants, while it is considered to be more noble than aluminium in aqueous media. [66][67][68] Mostafa et al reported that copper(I/II) oxides were formed when copper was dissolved in weakly acidic organic media. 69 This could partially explain the dissolution of copper by 75 vol% D2EHPA in absence of LCO.…”

Section: Leaching Mechanismmentioning

confidence: 99%

Recovery of cobalt from lithium-ion battery cathode material by combining solvoleaching and solvent extraction

2022

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Section: Leaching Mechanismmentioning

confidence: 99%

Recovery of cobalt from lithium-ion battery cathode material by combining solvoleaching and solvent extraction

2022

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“…Carbon nanostructures such as fullerenes, carbon nanotubes and graphene are self-assembled during the arc-discharge, laser ablation and chemical vapour deposition processes [4]. It has been shown that fluids such as carbon dioxide and benzene under near-and super-critical conditions can be used as solvents for the creation of nanostructures [5][6][7][8][9][10][11][12][13]. Gas-liquid coexistence curves terminate at the critical points, where large clusters are formed by fluids' molecules and as a result, incident light, scattered by the clusters, cannot penetrate the fluids, which is known as critical opalescence [14].…”

Section: Introductionmentioning

confidence: 99%

“…In addition to their unusual characteristics, near-and super-critical fluids have been recognized as useful fluids from a technological point of view and therefore they are often used in chemical, electronic and environmental sciences and engineering. Reactions are encouraged [24], chemicals are extracted [25], semiconductors are cleaned and purified [26] and nanostructures are created [5][6][7][8][9][10][11][12][13] in super-critical fluids. In terms of the formation of nanostructures, carbon particles, onions, coils, needles and fibres were created in near-or super-critical carbon dioxide, benzene and their mixture [5][6][7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

“…Reactions are encouraged [24], chemicals are extracted [25], semiconductors are cleaned and purified [26] and nanostructures are created [5][6][7][8][9][10][11][12][13] in super-critical fluids. In terms of the formation of nanostructures, carbon particles, onions, coils, needles and fibres were created in near-or super-critical carbon dioxide, benzene and their mixture [5][6][7][8][9][10][11][12][13]. In this paper we demonstrate a bottom-up method of producing metal-containing carbon onions using benzene under sub-and super-critical conditions.…”

Section: Introductionmentioning

confidence: 99%

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Creation of metal-containing carbon onions via self-assembly in metallocene/benzene solution irradiated with an ultraviolet laser

Hayasaki¹,

Fukuda²,

Hasumura³

et al. 2012

Adv. Nat. Sci: Nanosci. Nanotechnol.

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We irradiate sub- and super-critical benzene, in which metallocene such as ferrocene or cobaltocene is dissolved, with a UV laser of 266 nm wavelength, and show that benzene and metallocenes are dissociated and iron- and cobalt-containing carbon onions (Fe@C and Co@C) are created. The operational temperature of the present method is much lower than that of conventional ones for the growth of nanomaterials and therefore coagulation among metal-containing carbon onions is avoided. The average diameters of the core iron and cobalt nanoparticles are, respectively, 7.5 and 7.2 nm, whereas the thickness of the layers of carbon onions surrounding the core metal particles is 3.2 nm in both Fe@C and Co@C cases. The metal-containing carbon onions show superparamagnetic characteristics.

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Qualification of TA6V alloy cleaning processes using supercritical CO2 cleaning, from coupled SEM, XPS, and TPD analyses

Charton

Avril

Besnard

et al. 2017

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Traditional industrial cleaning processes of titanium and titanium alloys use solvents which are potentially toxic and environmentally harmful. Carbon dioxide, which is nontoxic, nonflammable, recyclable, and available on a large scale, is a potential substitute for these solvents. Indeed, the zero surface tension of supercritical CO2 (SC-CO2) provides a significant advantage over liquid and aqueous solutions, and facilitates the access to small structures, while a high diffusion coefficient allows a fast rate of mass transfer. Moreover, its viscosity and density can be adjusted by tuning pressure and temperature. In this study, the performances of solvent-assisted SC-CO2 process are compared to traditional TA6V alloy cleaning processes. The efficiency of residual oil removal from a TA6V surface has been investigated by several techniques such as x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). While XPS gives a measure of the so-called relative atomic surface concentration of carbon, which is commonly used to characterize cleanliness of the surface in the nanometer range, both EPMA and SEM provide elementary analysis at μm3 range and are often associated with characterizing morphologies of protuberances. Temperature programmed desorption coupled to a quadrupole mass spectrometer has also been used to obtain qualitative information on the nature and the relative amounts of the species degassed from the polluted and cleaned material surfaces.

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Creation of spherical carbon nanoparticles and clusters from carbon dioxide via UV dissociation at the critical point

Cited by 3 publications

References 39 publications

Recovery of cobalt from lithium-ion battery cathode material by combining solvoleaching and solvent extraction

Recovery of cobalt from lithium-ion battery cathode material by combining solvoleaching and solvent extraction

Creation of metal-containing carbon onions via self-assembly in metallocene/benzene solution irradiated with an ultraviolet laser

Qualification of TA6V alloy cleaning processes using supercritical CO2 cleaning, from coupled SEM, XPS, and TPD analyses

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