Raman microspectroscopy of soot and related carbonaceous materials: Spectral analysis and structural information

Sadezky, A.; Muckenhuber, H.; Grothe, Hinrich; Nießner, Reinhard; Pöschl, Ulrich

doi:10.1016/j.carbon.2005.02.018

Cited by 3,856 publications

(2,954 citation statements)

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“…For characterization of the carbon morphology, Raman spectra were recorded for all catalysts (Figure 7a,b). The analysis of the Raman spectra was made in relation to literature on carbon blacks [33,34]. All samples reveal the typical shape of carbon blacks with distinct D-band and G-band intensities.…”

Section: Resultsmentioning

confidence: 99%

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Influence of the Structure-Forming Agent on the Performance of Fe-N-C Catalysts

et al. 2018

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Abstract:In this work, the influence of the structure-forming agent on the composition, morphology and oxygen reduction reaction (ORR) activity of Fe-N-C catalysts was investigated. As structure-forming agents (SFAs), dicyandiamide (DCDA) (nitrogen source) or oxalic acid (oxygen source) or mixtures thereof were used. For characterization, cyclic voltammetry and rotating disc electrode (RDE) experiments were performed in 0.1 M H 2 SO 4 . In addition to this, N 2 sorption measurements and Raman spectroscopy were performed for the structural, and elemental analysis for chemical characterization. The role of metal, nitrogen and carbon sources within the synthesis of Fe-N-C catalysts has been pointed out before. Here, we show that the optimum in terms of ORR activity is achieved if both N-and O-containing SFAs are used in almost similar fractions. All catalysts display a redox couple, where its position depends on the fractions of SFAs. The SFA has also a strong impact on the morphology: Catalysts that were prepared with a larger fraction of N-containing SFA revealed a higher order in graphitization, indicated by bands in the 2nd order range of the Raman spectra. Nevertheless, the optimum in terms of ORR activity is obtained for the catalyst with highest D/G band ratio. Therefore, the results indicate that the presence of an additional oxygen-containing SFA is beneficial within the preparation.

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Section: Resultsmentioning

confidence: 99%

“…These are assigned to heteroatoms in carbon and polyaromatic hydrocarbons, respectively [33,34,36]. As an example, the fit of the most active catalyst is provided in Figure 7c.…”

Section: Resultsmentioning

confidence: 99%

Influence of the Structure-Forming Agent on the Performance of Fe-N-C Catalysts

et al. 2018

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“…The Raman spectrum for the material at approximately 316 À0.172 V, a potential very close to the open circuit one, shows 317 the typical features for carbon materials [27]. Two broad and 318 strongly overlapping bands at about 1350 cm À1 and at 319 1585 cm À1 , appear.…”

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confidence: 83%

Effect of surface chemistry on electrochemical storage of hydrogen in porous carbon materials

Bleda-Martı́nez

Pérez

Linares-Solano

et al. 2008

Carbon

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A B S T R A C TPorous carbon materials, with different porosities and surface chemistry have been prepared and characterized to obtain a better understanding of the mechanism of the electrochemical storage of hydrogen. The hydrogen storage capacity depends, not only on the porosity of the material, but also on the surface chemistry, which is a critical factor. The results show that the higher the amount of surface oxygen groups, the lower is the hydrogen uptake. Measurement of the number of active carbon sites shows the important role of the unsaturated carbon atoms in the process. In situ Raman spectroscopy has been used in order to further explore the structural changes in the carbon material during the chargedischarge processes. This technique has allowed us to observe the formation of the C(sp 2 )AH bonds during the cathodic process and its reversibility during the oxidation step.Ó 2008 Published by Elsevier Ltd. 29 Introduction 30Carbon materials have been extensively studied as electrodes 31 for energy storage devices since they present a very interest-32 ing electrochemical behaviour. These materials may have 33 high electrical conductivity and can both donate and accept 34 electrons [1]. Carbon electrodes have a good polarizability 35 and their properties are tuneable depending on the porosity, 36 thermal treatment, microtexture, hybridization, content of 37 heteroatoms, etc. Moreover, they are chemically stable in 38 most solvents and present relatively low cost and easy pro-39 cessability [2]. One important application is in rechargeable 40 batteries in which carbon materials are used as a lithium res-41 ervoir at the negative electrode [1]. Additionally, the storage of 42 energy in supercapacitors, based on the electrical double 43 layer and pseudocapacitance of carbon materials, has also 44 been deeply analysed with very promising results [2][3][4]. 45A different electrochemical application is the electrochem-46 ical storage of hydrogen by electrodecomposition of water in 47 alkaline medium at cathodic conditions. Several nanostruc-48 tured carbon materials, mainly nanotubes (CNT), have been 49 tested for this application [5][6][7][8][9][10][11]. However, the results ob-50 tained present an important scattering. In fact, taking into ac-51 count theoretical calculations and experimental results, it is 52 highly unlikely that a significant amount of hydrogen can 53 be stored in CNT [8]. The different results could be justified 54 by the different degree of purity of the samples (CNT often 55 contain amorphous and disordered carbonaceous material 56 or residual metal catalyst) [8,12]. 57 Porous carbons have also been extensively studied for this 58 application, giving higher values for hydrogen storage and 59 much better reproducibility. Probably, the most relevant re-60 search in this area has been done by Beguin, Frackowiak 61 and co-workers [13][14][15][16][17][18][19]. Similar results have been obtained 62 by other authors using ordered porous carbons with tailored 63 pore size [12], carbon blacks [...

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“…4 and Table 3. In the first order spectra (1000-2000 cm -1 ) the disorder induced (D) and graphite (G) bands appear at 1360 and 1580 cm -1 , respectively [54,55]. Of the first order peaks, the D band is the most prominent across all samples.…”

Section: Degree Of Graphitizationmentioning

confidence: 94%

Properties of mesoporous carbon modified carbon felt for anode of all-vanadium redox flow battery

Schmidt

Cao

2016

Sci. China Mater.

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A novel anode material for all-vanadium redox flow battery was synthesized by dispersion coating of sol-gel processed (resorcinol-furaldehyde) mesoporous carbon (MPC) onto the surface of polyacrylonitrile carbon felt (CF). The coated samples were then annealed at 900°C and 1100°C and the subsequent morphology, surface chemistry, and electrochemical properties of the MPC coated CF were characterized and compared with an uncoated CF. Addition of the MPC coating is shown to dramatically increase surface area while also increasing the number of active surface oxygen groups particularly for samples annealed at 1100°C. MPC coating shows a mixed effect on electrochemical properties. Characterization with cyclic voltammetry reveals the introduction of MPC coating provides roughly 30% increase in peak current density for the oxidation and reduction reactions of the V(IV)/V(V ) redox couple, which is attributed to the significantly increased number of active reaction sites. However, MPC coating seems to be accompanied by a reduction in conductivity as demonstrated by increased redox peak separation and charge transfer resistance. This negative effect on conductivity can be mitigated by heat treatment (at or above 1100°C) which improves surface graphitization reducing redox peak separation and charge transfer resistance such that it is comparable with uncoated samples.

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Raman microspectroscopy of soot and related carbonaceous materials: Spectral analysis and structural information

Cited by 3,856 publications

References 36 publications

Influence of the Structure-Forming Agent on the Performance of Fe-N-C Catalysts

Influence of the Structure-Forming Agent on the Performance of Fe-N-C Catalysts

Effect of surface chemistry on electrochemical storage of hydrogen in porous carbon materials

Properties of mesoporous carbon modified carbon felt for anode of all-vanadium redox flow battery

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