Raman spectroscopy of graphitic foams

Barros, Eduardo B.; Demir, Nasser; Filho, A. G. Souza; Fílho, J. Mendes; Jório, Ado; Dresselhaus, G.; Dresselhaus, M. S.

doi:10.1103/physrevb.71.165422

Cited by 141 publications

(100 citation statements)

References 15 publications

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“…The broad peak shape suggests multiple layers of graphene (i.e. graphite) likely consisting of both 2-D and 3-D graphite phases, 24,25 also consistent with the TEM. We conclude that the disorder is hence due to significant nitrogen doping, which undoubtedly contributes to the interesting electrochemical behavior of the CNS discussed below.…”

Section: Resultssupporting

confidence: 56%

Growth and Electrochemical Characterization of Carbon Nanospike Thin Film Electrodes

Sheridan

Hensley

Lavrik

et al. 2014

J. Electrochem. Soc.

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We report the growth of a nanospiked, carbon thin film electrode by an inexpensive, non-catalytic plasma enhanced CVD process on Si substrates. The electron transfer kinetics for various redox probes of these carbon nanospikes (CNS) were determined and compared with glassy carbon and CNS exposed to oxygen plasma or a high temperature ammonia soak. The results indicate that CNS can be used as a practical alternative to GC for various electroanalysis applications. These electrodes also exhibited activity and stability toward the oxygen reduction reaction, suggesting there potential use as electrocatalyst supports. Finally, the ability to deposit conformal thin films of CNS on a 3-D architecture for use as an electrode was demonstrated. Carbon electrodes are commonly used in electrochemical applications such as sensing and electrocatalysis. This class of electrode is often touted for being inexpensive, highly conductive, electrochemically stable, amenable to surface chemistry modifications, and having a wide electrochemical window. While the electrochemistries of standard carbon electrodes like glassy carbon and carbon black have been thoroughly studied, newly developed nanoscale carbon materials present a potent new class of carbon electrodes to explore. A great deal of attention has focused on highly ordered carbon nanomaterials like graphene 1-3 and carbon nanotubes, 4 in addition to less ordered carbons like pyrolized graphite, 5 carbon foams 6 and fibers. 7One approach to forming nanoscale carbon electrodes is through thin film deposition, which can produce free standing electrodes for easy incorporation into sensors, microelectronic components, and energy storage and conversion devices. Carbon thin films having a range of structural and electrochemical properties have been formed by techniques including photoresist pyrolysis, 8-10 sputtering, 11,12 and pulsed laser-arc deposition, 13 among others. Chemical vapor deposition (CVD), which is best known for its use in the microelectronics industry for fabricating thin films of semiconductors, metals, alloys and dielectrics, is another option for carbon thin film formation. Fundamental research into CVD technologies led to the development of numerous variations, such as metal-organic CVD (MOCVD) and plasma-enhanced CVD (PECVD). CVD in its various forms has been used since the mid-90's to synthesize nanostructured carbons including carbon nanotubes, 14 Nanostructured electrodes -those with controlled architectures at the nanoscale -often possess high surface area, tunable surface functionality, increased electrocatalytic activity, spatial control and unique diffusion properties (which can lead to higher sensitivity). 19Here we report the formation and electrochemical characterization of nanostructured carbon thin film electrodes, which we refer to as carbon nanospikes (CNS) due to the primary morphological characteristic of tapered spikes approximately 50 nm in length. The nanospikes herein are grown on Si wafer using non-catalytic PECVD in the presence of ammon...

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Section: Resultssupporting

confidence: 56%

Growth and Electrochemical Characterization of Carbon Nanospike Thin Film Electrodes

Sheridan

Hensley

Lavrik

et al. 2014

J. Electrochem. Soc.

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“…The recent development of graphitic foams 6 characterized by highly aligned graphitic structures has attracted attention for thermal management devices 7 , and with unusually high thermal conductivity-to-weight ratios such graphitic carbons are promising aeronautical and aerospace industrial materials. Among the many methods for carbon nanostructure growth [8][9][10] , the organometallic approach [11][12][13] has been widely used and is one of the principal synthetic methods.…”

Section: Introductionmentioning

confidence: 99%

Layered Graphitic Carbon Host Formation during Liquid-free Solid State Growth of Metal Pyrophosphates

et al. 2012

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Original citationDiaz, C., Valenzuela, M. L., Lavayen, V. and O'Dwyer, C. (2012) 'Layered graphitic carbon host formation during liquid-free solid state growth of metal pyrophosphates', Inorganic Chemistry, 51 (11) AbstractWe report a successful ligand-and liquid-free solid state route to form metal pyrophosphates within a graphitic carbon matrix through a single step approach involving pyrolysis of previously synthesized organometallic derivatives of a cyclotriphosphazene. In this case, we show how single crystal Mn 2 P 2 O 7 can be formed either on the micro-or nanoscale in the complete absence of solvents or solutions by an efficient combustion process using rationally designed macromolecular trimer precursors, and present evidence and a mechanism for layered graphite host formation.Using in situ Raman spectroscopy, infrared spectroscopy, X-ray diffraction, high resolution electron microscopy, thermogravimetric and differential scanning calorimetric analysis, and near-edge X-ray absorption fine structure examination, we show evidence for the formation of a layered, graphitic carbon in the matrix and how the process occurs. The identification of thermally and electrically conductive graphitic carbon host formation is important for the further development of this general ligandfree synthetic approach for inorganic nanocrystal growth in the solid state, and can be extended to form a range of transition metals pyrophosphates. For important energy storage applications, the method gives the ability to form oxide and (pyro)phosphates within a conductive, intercalation possible, graphitic carbon as host-guest composites directly on substrates for high rate Li-ion battery and emerging alternative positive electrode materials.

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“…The samples used for establishing the empirical equation (3.5) can be considered as model samples and the use of equation (3.5) for any general sp 2 carbon-based material would probably need to be generalized. One example of such a study has been made for carbon foams (Barros et al 2005).…”

Section: (C) One-dimensional Defects Represented By the Boundaries Ofmentioning

confidence: 99%

Defect characterization in graphene and carbon nanotubes using Raman spectroscopy

Dresselhaus

Jório

Filho

et al. 2010

Phil. Trans. R. Soc. A.

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630

444

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This review discusses advances that have been made in the study of defect-induced double-resonance processes in nanographite, graphene and carbon nanotubes, mostly coming from combining Raman spectroscopic experiments with microscopy studies and from the development of new theoretical models. The disorder-induced peak frequencies and intensities are discussed, with particular emphasis given to how the disorder-induced features evolve with increasing amounts of disorder. We address here two systems, ionbombarded graphene and nanographite, where disorder is represented by point defects and boundaries, respectively. Raman spectroscopy is used to study the 'atomic structure' of the defect, making it possible, for example, to distinguish between zigzag and armchair edges, based on selection rules of phonon scattering. Finally, a different concept is discussed, involving the effect that defects have on the lineshape of Raman-allowed peaks, owing to local electron and phonon energy renormalization. Such effects can be observed by near-field optical measurements on the G feature for doped single-walled carbon nanotubes.

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Raman spectroscopy of graphitic foams

Cited by 141 publications

References 15 publications

Growth and Electrochemical Characterization of Carbon Nanospike Thin Film Electrodes

Growth and Electrochemical Characterization of Carbon Nanospike Thin Film Electrodes

Layered Graphitic Carbon Host Formation during Liquid-free Solid State Growth of Metal Pyrophosphates

Defect characterization in graphene and carbon nanotubes using Raman spectroscopy

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