Characterisation of onion-like carbon fabricated by annealing nanodiamond

Zou, Qin; Li, Y. G.; Wang, M. Z.; Zou, Liang‐Hua; Zhao, Yucheng

doi:10.1179/143307510x12777574294902

Cited by 4 publications

(5 citation statements)

References 16 publications

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“…As far as the average distances between the individual CNO layers are concerned, it is apparent that all CNOs whose formation is predicted to be kinetically inhibited, i.e., C 20 @C 60 , C 20 @C 80 , and C 60 @C 180 , exhibit shorter distances than the experimentally observed 3.35 Å for a five-layered CNO . This lends further credence to our prediction of the large kinetic barrier to their formation.…”

Section: Resultssupporting

confidence: 77%

“…CNOs were first discovered by Iijima, several years before Kroto and Smalley’s seminal synthesis of buckminsterfullerene (see Figure ), and later described in detail by Ugarte . Since their discovery, CNOs have been prepared in a number of experiments, − and their structure, morphology, and other properties have been investigated systematically. − CNOs have been suggested for use in applications like energy storage, , high-performance wear resistance materials, , superconductive materials, − and biomaterials. ,− Their synthesis, chemistry, and applications have been reviewed in detail …”

Section: Introductionmentioning

confidence: 99%

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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: Resultssupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

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

Hashmı

Lein

2018

J. Phys. Chem. C

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“…The most critical process parameters are annealing temperature, time, pressure, and atmosphere. Annealing conditions reported in literature vary substantially, with temperatures ranging from 300 to 1900 • C. Zou et al observed that around 600 • C the edges of ND particles start to transform into amorphous carbon, resulting in a complete amorphization of the ND surface at ∼750 • C, followed by graphitization along the edge sites at 850 • C [30][31][32][33][34]. More recent studies found that below 900 • C the ND surface is reconstructed into graphite, but the diamond core is unaltered.…”

Section: Introductionmentioning

confidence: 99%

Raman spectroscopy study of the nanodiamond-to-carbon onion transformation

McDonough²,

et al. 2013

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Here, we present a comprehensive study analyzing early stages of the transformation of detonation nanodiamond (ND) powder to graphitic carbon onions via thermal annealing in argon atmosphere. Raman spectroscopy was employed to monitor this transformation, starting with the sp³-to-sp² conversion of the ND surface at the onset of the graphitization process. Additionally, transmission electron microscopy, x-ray diffraction, and thermogravimetric analysis were used to supplement the structural information obtained from Raman spectroscopy and allow for an accurate interpretation of the obtained Raman data. The effect of the annealing time on the transformation process was also studied to determine the kinetics of the conversion at low temperatures. The results presented in this study complement previous work on ND annealing and provide deeper insight into the nanodiamond-to-carbon onion conversion mechanism, in particular the time and size dependence. We present further evidence for the existence of a disordered sp² phase as an intermediate step in the transformation process.

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“…Carbon nano-onions (CNOs), concentrically multilayered fullerenes, are among the least studied carbon allotropes. Nanodiamond-derived carbon nano-onions (NCNOs) with an average diameter of ∼5–7 nm can be prepared in bulk quantities with homogeneous size distribution and high purity. − NCNOs have a BET surface area of ∼520 m 2 /g, electrical conductivity of 4 S·cm –1 and high mesoporosity . Thus, NCNO is a suitable candidate for high-performance composite electrodes for supercapacitor applications.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Study of Functionalized Carbon Nano-Onions for High-Performance Supercapacitor Electrodes

et al. 2012

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Carbon nano-onions (NCNOs), concentrically multilayered fullerenes, are among the least studied carbon allotropes. NCNOs have high surface area, high mesoporosity, facile electrical conductivity, and electrochemical stability. NCNOs are chemically oxidized (ONCNOs) to introduce hydrophilic functional groups, improving their wettability for use in supercapacitor electrodes. RuO2·xH2O/ONCNOs composites are prepared by chemical precipitation of RuO2 on ONCNOs, optimized for homogeneous distribution and maximum utilization of the metal oxide nanoparticles. The materials are characterized by high-resolution transmission electron microscopy, N2 absorption–desorption isotherm, and thermogravimetric analysis. Electrochemical performance of the electrodes is studied by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance measurements in 1.0 M H2SO4. While ONCNOs have specific capacitance of 45 F·g–1, a composite with 67.5 wt.% RuO2 has specific capacitance of 334 F·g–1 at a potential sweep rate of 20 mV·s–1 with high power (242.8 kW·kg–1) and high energy density (11.6 Wh·kg–1). Both the ONCNO and the composites show excellent capacitance behaviors even at very high potential scan rates (>8 V·s–1). Simple preparation of high-purity NCNOs and excellent electrochemical behavior of functionalized NCNOs make them a promising electrode material in supercapacitor applications.

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Characterisation of onion-like carbon fabricated by annealing nanodiamond

Cited by 4 publications

References 16 publications

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

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

Raman spectroscopy study of the nanodiamond-to-carbon onion transformation

Electrochemical Study of Functionalized Carbon Nano-Onions for High-Performance Supercapacitor Electrodes

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