Combined XPS and TPD study of oxygen-functionalized carbon nanofibers grown on sintered metal fibers

Rosenthal, Dirk; Ruta, Marina; Schlögl, Robert; Kiwi‐Minsker, Lioubov

doi:10.1016/j.carbon.2010.01.029

Cited by 195 publications

(141 citation statements)

References 31 publications

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“…Therefore, the CO/CO 2 evolution curve derived in this study indicates that ozone and nitric acid add partly different functional groups on the PCNF/CSCNF/ACF surface. Overall, ozone oxidation adds more carboxyl/phenol groups and fewer anhydride/carbonyl groups to the carbon surface than does nitric acid, which was supported by the previous reports about CNF functionality analysis by TPD/XPS (Rosenthal et al 2010). Figure 8 shows the effect of HNO 3 /O 3 concentration on the amount of surface functional groups analyzed by TPD for the PCNFs, CSCNFs and ACFs.…”

Section: Functional Groupssupporting

confidence: 82%

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Adsorption of ammonia and water on functionalized edge-rich carbon nanofibers

2012

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The preparation, characterization and ammonia and water adsorption properties of edge-rich carbon nanofibers (CNFs) were studied, including platelet CNFs (PCNFs) and cup-stacked CNFs (CSCNFs). Since PCNFs and CSCNFs have many chemically active exposed edges, functionalization by oxidizing the edges was carried out by ozone stream and by nitric acid. Transmission electron microscopy, N 2 adsorption isotherms and temperatureprogrammed desorption analysis showed that the nitric acid treatment partly destroyed the graphite structure of the PCNFs and created acid functional groups and micropores, whereas the ozone treatment created functional groups without damaging the structure. Ammonia adsorption isotherms clarified that NH 3 adsorption on PCNFs and CSCNFs occurred mainly on oxygen-containing groups, whereas the adsorption on activated carbon fibers (ACFs) occurred on both oxygen-containing groups and the carbon surface without the functional groups, and the CSCNFs showed larger amounts of adsorbed ammonia compared to the PCNFs. Especially at a relatively low pressure range (<0.2 atm), the PCNFs/CSCNFs/ACFs showed the same ammonia adsorption mechanism; that is, the one-to-one interaction between oxygen atoms in the functional groups and hydrogen atoms in ammonia molecules. In addition, the adsorption on the ACFs appeared to occur mainly by interaction with the carbon surface at relatively high pressure (0.3-1.0 atm). Our experimental results and previous findings suggest that NH 3 adsorption on PCNFs is due mainly to NH. . .O hydrogen bonding between oxygen-containing groups and ammonia rather than to chemical bonding.

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Section: Functional Groupssupporting

confidence: 82%

“…TPD analysis is a well-established method for characterizing the functional groups on carbon materials such as CNFs (Rosenthal et al 2010), CNTs (Delhaes et al 2006) and activated carbon (Figueiredo et al 1999). In this experiment, 200 mg of each sample was put on a ceramic boat and placed in a quartz tube.…”

Section: Tpd Analysismentioning

confidence: 99%

Adsorption of ammonia and water on functionalized edge-rich carbon nanofibers

2012

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“…High resolution spectra of the O 1s peak are presented in Figure 4(c). The O 1s peak of the CNF material has a maximum at about 533 eV, which can be related to water absorption [40]. The functionalized CNF spectrum was deconvoluted in two peaks, at 533 eV and at 531.2 eV, which corresponds to OH hydroxyl group [41].…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

Silva

Salas

Nedev

et al. 2017

Journal of Nanomaterials

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Carbon nanohybrid material (CNF/ -Fe 2 O 3 ) was obtained via a modified sol-gel technique consisting of two steps: functionalization of carbon nanofibers (CNF) in H 2 SO 4 /HNO 3 followed by synthesis using Fe(NO 3 ) 3 •9H 2 O. As a result, the iron content of the CNF/ -Fe 2 O 3 was increased by more than twice from about 40% to about 87% mass percent, compared to the pristine CNF and oxidized CNF specimens, as proved by energy dispersive X-ray fluorescence. Scanning electron microscopy images exhibited "cumulus" on the CNF/ -Fe 2 O 3 specimen surface, which showed the highest iron mass percentage, proved by energy dispersive X-ray spectroscopy. Transmission electron microscopy images confirmed attachment of -Fe 2 O 3 cumulus to the inner and outer surfaces of the CNF walls after synthesis. The characteristic peaks of Fe 2p 3/2 and Fe 2p 1/2 appeared in the XPS spectra obtained on CNF/ -Fe 2 O 3 . In addition, X-ray diffraction (XRD) results indicated formation of -Fe 2 O 3 during the synthesis process. The Raman spectrum of the CNF/ -Fe 2 O 3 sample displays peaks with positions close to characteristic peaks of highly crystalline and monodisperse maghemite nanocrystallites. The synthesis of CNF/ -Fe 2 O 3 leads to an increase in the hydrophilicity of CNF and magnetic properties at room temperature.

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“…The temperature of CO desorption from each functional group depends not only on the sample properties, but also on the TPD instrument and measurement conditions, so it is generally difficult to assign the types of oxygen functional groups simply by deconvolution of the CO-TPD profile. 59,61 We therefore performed FT-IR analyses to obtain further information on the types of functionalities in the oxidized ZTC (Figure 3c). The aforementioned ethers, phenols, and quinones generally give CO stretching (10001300 cm ¹1 ), 62 OH stretching (32003400 cm…”

Section: Resultsmentioning

confidence: 99%

Large Pseudocapacitance in Quinone-Functionalized Zeolite-Templated Carbon

Itoi

Nishihara²,

Ishii³

et al. 2013

Bulletin of the Chemical Society of Japan

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Zeolite-templated carbon (ZTC), which can be obtained as a negative replica of a zeolite, consists of buckybowllike nanographenes assembled into a three-dimensional regular network. ZTC is characterized not only by this unique framework structure but also by a very large number of carbon edge sites. In this paper, we report that the edge sites of ZTC are easily functionalized by a large amount of quinone groups through electrochemical oxidation unlike general carbonaceous materials, and the quinone-functionalized ZTC shows a high electrochemical capacitance (ca. 300 500 F g ¹1 ) in an aqueous electrolyte solution (1 M H 2 SO 4 ) as a result of the large pseudocapacitance derived from a quinone/hydroquinone redox couple. Moreover, ZTC keeps its high capacitance even after thousands of charge discharge cycles.Fullerenes, 1 single-walled carbon nanotubes (SWCNTs), 2,3 and graphenes 4,5 are nanocarbon materials with 0D, 1D, and 2D topologies, respectively. Though fullerenes form poorly conductive van der Waals crystals, SWCNTs 6,7 and graphenes 811 are electrically conductive, and are promising as electrode materials for electrochemical capacitors. 12 Their building unit, a graphene sheet, has a large theoretical surface area (2630 m 2 g ¹1 ), and therefore potentially has a large capacitance. However, the actual BrunauerEmmettTeller (BET) surface areas of SWCNTs 13 and graphenes 8 are at most 1250 and 705 m 2 g ¹1 , respectively, because of the aggregation/stacking of the graphene sheets as a result of strong van der Waals interactions. To expose the entire surface, a graphene sheet has to be formed into a self-standing 3D network, like carbon schwarzite 14,15 or pillared graphene, 16 both of which are imaginary materials and have only been proposed theoretically. Thus far our group has demonstrated that it is possible to synthesize a graphene-based architecture with a 3D topology inside the confined-nanospace network of a zeolite crystal, as shown in Figures 1a1c. 1720The zeolite-templated carbon (ZTC) thus obtained consists of a buckybowl-like nanographene assembled into a 3D regular network (Figures 1c and 1d). Both sides of the buckybowllike unit are fully exposed, and, in addition, the narrow nanographene-based framework has a significant number of edge sites. 18 Consequently, ZTC has a very large geometric (theoretical) surface area of 3432 m 2 g ¹1 , and such a large surface area has indeed been observed experimentally.18 ZTC possesses unique spin/magnetic properties 21 and is predicted to have a unique band structure. 22 Moreover, it has a high hydrogen-storage capacity 23,24 and superior performance as an electrode for electrochemical capacitors.2527 Modifications of ZTC with electrochemically active species are expected to further enhance its performance. Graphene-based materials are generally modified by doping of graphene with other functional components such as metal nanoparticles, 2830 metal oxides/ hydroxides, 3134 and conductive polymers. 35 Another modification method is to functionalize graphenes...

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Combined XPS and TPD study of oxygen-functionalized carbon nanofibers grown on sintered metal fibers

Cited by 195 publications

References 31 publications

Adsorption of ammonia and water on functionalized edge-rich carbon nanofibers

Adsorption of ammonia and water on functionalized edge-rich carbon nanofibers

Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

Large Pseudocapacitance in Quinone-Functionalized Zeolite-Templated Carbon

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