Raman Studies of Carbon Nanostructures

Jório, Ado; Filho, A. G. Souza

doi:10.1146/annurev-matsci-070115-032140

Cited by 125 publications

(79 citation statements)

References 134 publications

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“…Raman spectroscopy is commonly used to identify the quality or graphitic nature of carbons based on the intensity of D and G bands [35,42,43]. The D band in the Raman shift indicates amorphous or disordered carbon and the G band indicates graphitic or filamentous carbon.…”

Section: H2o + Co = H2 + Co2 Equationmentioning

confidence: 99%

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Zhang

Williams

2016

Journal of Analytical and Applied Pyrolysis

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A range of process conditions have been investigated to maximise the production of carbon nanotubes (CNTs) and/or hydrogen from waste tyres. A two-stage pyrolysis-catalytic reactor system was used and the influence of catalyst temperature (700, 800 and 900 °C), tyre: catalyst ratio (1:0.5, 1:1 and 1:2) and steam input (water injection 0, 2 and 5 ml h -1 ) to the second catalyst stage were investigated. The catalyst used was a Ni/Al2O3 catalyst prepared by a wetness impregnation technique. Carbon was deposited on the catalyst surface during pyrolysis-catalysis increasing with increasing catalyst temperature and also increasing as the tyre: catalyst ratio was raised. Examination of the carbon showed it to be composed of largely filamentous type carbons, producing 253.7 mg g -1 tyre of filamentous carbons at a tyre: catalyst ratio of 1:1 and catalyst temperature of 900 °C. A significant proportion of the deposited filamentous carbons were multi-walled carbon nanotubes as shown by transmission electron microscopy characterisation. The introduction of steam to the process enhanced hydrogen production, producing a maximum of 34.69 mmol g -1 tyre at a water injection rate of 5 ml h -1 .4

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Section: H2o + Co = H2 + Co2 Equationmentioning

confidence: 99%

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Zhang

Williams

2016

Journal of Analytical and Applied Pyrolysis

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“…Raman spectroscopy is one of the most informative techniques for the characterization of carbon nanostructures . The Raman absorptions for NDs and CNOs and for their nitrogen‐doped structures have been identified as the origin of the D and G peaks and of the second order the D peak .…”

Section: Resultsmentioning

confidence: 99%

“…Raman spectroscopy is one of the most informativet echniques for the characterization of carbon nanostructures. [37,38] The Raman absorptions for NDs and CNOs and for their nitrogendoped structures have been identified as the origin of the D and G peaks ando ft he second order the D peak. [39] The G and D peaks lie at around 1560a nd 1360cm À1 for visible excitation, respectively.T he Ramans pectra of carbon films are dominated by the sp 2 sites (G band).…”

Section: Spectroscopic and Thermogravimetric Characteristics Of Cnos mentioning

confidence: 99%

Improvement of the Structural and Chemical Properties of Carbon Nano‐onions for Electrocatalysis

et al. 2017

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Heteroatom doping of carbon nanostructures is a convenient tool to control their physicochemical properties and to make them suitable for various applications. Carbon nano‐onions (CNOs) doped with nitrogen (N‐CNOs) have been prepared by annealing aminated‐nanodiamond particles (AM‐NDs) at different temperatures (1150, 1450 and 1650 °C) in an inert He atmosphere. Their physicochemical properties were compared with those of pristine CNOs obtained from non‐functionalized NDs under the same experimental conditions. The carbon nanostructures were characterized using transmission (TEM) and scanning (SEM) electron microscopy, X‐ray powder diffraction (XRD), Raman and Fourier transform infrared (FTIR) spectroscopy, porosimetry, and differential‐thermogravimetric analyses (TGA‐DTG). Their physicochemical properties are systematically discussed for undoped and for the nitrogen‐doped CNO samples. The results reveal that the surface morphology and the structure of undoped and nitrogen‐doped CNOs vary with the annealing temperature. All of these materials were electrochemically tested as electrode materials for enzyme‐free catalysis of hydrogen peroxide. The nitrogen‐doped carbon nanostructures have a higher catalytic activity than undoped nanostructures obtained under the same experimental conditions.

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“…In MG nanohybrids, there are two dominate bands centered at ∼1358 and ∼1575 cm −1 which belong to rGO nanosheets. The former peak ( D peak) is attributed to defect‐ and disorder‐related structures in carbon materials, and the latter peak ( G peak) is associated with the stretching vibration of the C−C bond in graphite . The broad 2 D band appeared at ∼ 2680–2690 cm −1 shows the few‐layer nature of the rGO .…”

Section: Resultsmentioning

confidence: 99%

Graphene Oxide-Directed Tunable Assembly of MoS₂ Ultrathin Nanosheets for Electrocatalytic Hydrogen Evolution

2017

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Three dimensional (3D) hierarchical architectures based on molybdenum disulfide (MoS 2 ) and reduced graphene oxide (rGO) are synthesized through a mixed solvothermal method. By simply increasing the amount of graphene oxide (GO) during the synthesis, the 3D assembly of MoS 2 can be tuned from nanoflowers to cross-linked nanosheets firmly attached to rGO. The structural and compositional analysis show that MoS 2 nanostructures in the hybrids are constituted by ultrathin nanosheets with single or a few layers, and the GO precursor is reduced as rGO simultaneously. Due to the synergetic effects of rGO nanosheets and controllable assembly in MoS 2 ultrathin nanostructures, the resulting nanohybrids show optimized electrocatalytic hydrogen evolution properties in 0.5 M H 2 SO 4 solution. This work provides a facile method to increase the efficiency of hydrogen production for MoS 2 based materials and their analogues via a tunable bottom-up assembly strategy.[a] Dr.

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Raman Studies of Carbon Nanostructures

Cited by 125 publications

References 134 publications

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Improvement of the Structural and Chemical Properties of Carbon Nano‐onions for Electrocatalysis

Graphene Oxide-Directed Tunable Assembly of MoS₂ Ultrathin Nanosheets for Electrocatalytic Hydrogen Evolution

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Raman Studies of Carbon Nanostructures

Cited by 125 publications

References 134 publications

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Carbon nanotubes and hydrogen production from the pyrolysis catalysis or catalytic-steam reforming of waste tyres

Improvement of the Structural and Chemical Properties of Carbon Nano‐onions for Electrocatalysis

Graphene Oxide-Directed Tunable Assembly of MoS2 Ultrathin Nanosheets for Electrocatalytic Hydrogen Evolution

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Graphene Oxide-Directed Tunable Assembly of MoS₂ Ultrathin Nanosheets for Electrocatalytic Hydrogen Evolution