Dynamics of defects and surface structure formation in reticulated vitreous carbon

Gonçalves, Emerson Sarmento; Rezende, Mirabel Cerqueira; Ferreira, N.G.

doi:10.1590/s0103-97332006000300008

Cited by 19 publications

(7 citation statements)

References 14 publications

(23 reference statements)

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“…These two peaks are the D (defective carbon) and G (graphitic basal plane carbon) bands typically found in this form and repersent the relative intensity for polycrystalline and noncrystalline graphitic carbon. 41 Furthermore, graphitic materials usually have a G′ or 2D band at ∼2600 cm −1 that, in the present case, may be either very broad or not present due to structural disorder or damaging of lattice. 42 Combining these findings with those previously discussed for the XPS and IR characterization, we can reasonably surmise that, upon pyrolysis, PEI-C 60 is converted from a cross-linked amine-rich polymer composite to a disordered N-doped graphitic material characterized by the presence of pyrrolic, pyridinic, and oxidized nitrogens.…”

Section: Energy and Fuelsmentioning

confidence: 69%

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀

Andreoli

Barron

2015

Energy Fuels

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Nitrogen functionalities play a crucial role in determining the sorption capacity and selectivity of organic-based CO 2 solid sorbents. Two main types of solid sorbents are (1) amine-rich compounds used for their distinctive reactivity of amino groups with CO 2 , and (2) N-doped carbons where CO 2 -philic nitrogens impart chemoselectivity to otherwise pure carbon physisorbents. It is of interest to correlate the CO 2 sorption performance of these materials to the chemical changes involved in going from amine-rich polymers to N-doped carbons. To this end, we pyrolyzed amine-rich polyethylenimine-C 60 (PEI-C 60 ) to N-doped carbons and focused our investigation on how chemical changes and CO 2 capture correlate. In particular, we found that upon thermal treatment in inert atmosphere, PEI-C 60 undergoes an inversion in CO 2 sorption behavior. PEI-C 60 , which better absorbs CO 2 at high temperature (0.13 g/g at 90°C), is converted into pyrolyzed materials with improved CO 2 capture performance at low temperature (0.12 g/g at 25°C). X-ray photoelectron spectroscopy (XPS), Fourier transfer infrared (FTIR), and Raman characterizations reveal a progressive conversion of PEI-C 60 to disordered graphitic carbon including pyrrolic and pyridinic aromatic nitrogens, where the transition from one material to the other goes through a drastic drop of CO 2 capture performance due to the breakdown of the carbon backbone of PEI.

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Section: Energy and Fuelsmentioning

confidence: 69%

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀

Andreoli

Barron

2015

Energy Fuels

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“…Surface defects on the RVC strut surface, such as ripples can often be traced to the manufacturing process and have been considered in detail elsewhere [40]. The degree of graphitisation of RVC can be characterised, in comparison to other carbon materials, by Raman spectroscopy and X-ray diffraction.…”

Section: The Structure Of Rvcmentioning

confidence: 99%

The continued development of reticulated vitreous carbon as a versatile electrode material: Structure, properties and applications

Walsh

Arenas

León

et al. 2016

Electrochimica Acta

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The limitations of 2-dimensional electrodes can be overcome by using threedimensional materials having sufficient porosity and active area while offering moderate mass transport rates and a relatively low pressure drop at controlled electrolyte flow rate. In concept, a wide variety of metal, ceramic and composite materials are possible but restrictions are imposed by the need to avoid materials degradation, while maintaining adequate electrical conductivity, sufficient robustness and the possibility of facile scale-up. Despite its fragility, one of the traditional electrode materials used as a porous, 3-dimensional electrode is carbon foam, particularly in the 97% vol. porous form of reticulated vitreous carbon, RVC. A timeline indicates that the history of this material dates back over 50 years to the mid1960s, when it was primarily used as an uncoated material in small-scale, laboratory electroanalysis. Surface modification and diverse coatings have considerably extended the use of RVC. Recent applications are found in sensors and monitors, electrosynthesis, environmental processing and energy conversion. This review highlights the fundamental structure and summarises the physicochemical properties of RVC. Fluid flow through various porosity grades of the material, their active electrochemical area and rates of mass transport are quantified. The diverse applications of RVC in energy conversion, environmental treatment and electrosynthesis are illustrated by selected examples from the authors' laboratories and others over the last 30 years. Recent research on coated RVC, energy conversion environmental remediation and sensors is highlighted. Critical areas deserving further research and development are proposed.

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“…Present within the spectra of Figure 4 is both a G band at 1,582 cm −1 and a D band at 1,350 cm −1 . The former is derived from the E 2g in-plane vibrational mode within aromatic rings and thus is indicative of the degree of graphitisation [33]; the latter relates to sp 3 carbons in the presence of isolated domains of aromaticity and so is indicative of the number of graphene flake edge sites or residual sp 3 sites associated with unreduced epoxide/hydroxyl groups [34]. The D band is a defect induced Raman feature and would not be seen in a purely crystalline sample [35].…”

Section: Resultsmentioning

confidence: 99%

Fabrication and Characterisation of the Graphene Ring Micro Electrode (GRiME) with an Integrated, Concentric Ag/AgCl Reference Electrode

Dickinson

Bromley

Andrieux

et al. 2013

Sensors

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We report the fabrication and characterisation of the first graphene ring micro electrodes with the addition of a miniature concentric Ag/AgCl reference electrode. The graphene ring electrode is formed by dip coating fibre optics with graphene produced by a modified Hummers method. The reference electrode is formed using an established photocatalytically initiated electroless deposition (PIED) plating method. The performance of the so-formed graphene ring micro electrodes (GRiMEs) and associated reference electrode is studied using the probe redox system ferricyanide and electrode thicknesses assessed using established electrochemical methods. Using 220 μm diameter fibre optics, a ∼15 nm thick graphene ring electrode is obtained corresponding to an inner to outer radius ratio of >0.999, so allowing for use of extant analytical descriptions of very thin ring microelectrodes in data analysis. GRiMEs are highly reliable (current response invariant over >3,000 scans), with the concentric reference electrode showing comparable stability (current response invariant over >300 scans). Furthermore the micro-ring design allows for efficient use of electrochemically active graphene edge sites and the associated nA scale currents obtained neatly obviate issues relating to the high resistivity of undoped graphene. Thus, the use of graphene in ring microelectrodes improves the reliability of existing micro-electrode designs and expands the range of use of graphene-based electrochemical devices.

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Dynamics of defects and surface structure formation in reticulated vitreous carbon

Cited by 19 publications

References 14 publications

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀

The continued development of reticulated vitreous carbon as a versatile electrode material: Structure, properties and applications

Fabrication and Characterisation of the Graphene Ring Micro Electrode (GRiME) with an Integrated, Concentric Ag/AgCl Reference Electrode

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Dynamics of defects and surface structure formation in reticulated vitreous carbon

Cited by 19 publications

References 14 publications

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C60

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C60

The continued development of reticulated vitreous carbon as a versatile electrode material: Structure, properties and applications

Fabrication and Characterisation of the Graphene Ring Micro Electrode (GRiME) with an Integrated, Concentric Ag/AgCl Reference Electrode

Contact Info

Product

Resources

About

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀

Correlating Carbon Dioxide Capture and Chemical Changes in Pyrolyzed Polyethylenimine-C₆₀