2015 | |
Articles: | |
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Ind. Crops Prod.,
70:332-340
2015
Resume: Six porous carbon materials, produced by hydrothermal treatment of flavonoid tannin and subsequent carbonization at 1173 K, were tested as electrodes of supercapacitors. Four of these carbons were doped with nitrogen by putting tannin in contact with ammonia before or during the hydrothermal treatment. The pyrolyzed hydrothermal carbons had moderate surface areas, within the range 442-684 m2 g-1, and nitrogen contents ranging from 0.7 to 8.0 wt.%. Specific capacitances as high as 320 F g-1 and normalized capacitances as high as 58 ?F cm-2 were measured at 2 mV s-1. These performances are comparable with those obtained with high surface area-activated carbons, whereas, normalized capacitances values are among the highest ever reported. Mesostructuration, within the range 3-13 nm, of these materials appears to be a good strategy to improve their electrochem. performances at higher scan rates. We confirmed the beneficial role of oxygen up to 18 wt.%, while an optimum in nitrogen content exists from 3 to 6 wt.%. [on SciFinder(R)] Equipe: Département CP2S : Chimie et électrochimie des matériaux |
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Carbon,
90(0):63-74
2015
Resume: Abstract Aminated tannin submitted to hydrothermal treatment led to nitrogen-doped gels in the absence of any cross-linker. Such gels were subcritically dried, freeze-dried or supercritically dried to obtain organic xerogels, cryogels and aerogels, respectively, having nitrogen contents between 3.0 and 3.7 wt.%. After pyrolysis at 900 °C, the materials presented nitrogen contents ranging from 1.9 to 3.0 wt.%, and surface areas as high as 860, 754 and 585 m2 g?1 for carbon aerogels, cryogels and xerogels, respectively. All of them displayed micropores associated with different mesopore volumes, depending on both the drying method and initial dilution of the precursor. When tested as supercapacitor electrodes, these carbon gels presented outstanding specific and normalised capacitances, up to 387.6 F g?1 and 69.5 ?F cm?2, respectively, at a scan rate of 2 mV s?1 in 4 mol L?1 H2SO4 aqueous solution. These performances are higher than those obtained with high apparent surface area-activated carbons, as the measured capacitances are indeed among the highest ever reported. The influence of nitrogen- and oxygen-based moieties was investigated, and optimal N and O contents of 2–3 and 17–18 wt.%, respectively, were observed. Equipe: Département CP2S : Chimie et électrochimie des matériaux |
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Electrochimica Acta,
161:403-407
2015
Resume: In this study, we examd. individual bismuth telluride nanowires (NWs) electrodeposited in polycarbonate membranes (PCM) used as sacrificial templates. It has been demonstrated that the compn. of Bi2Te3 is controlled by the electrodeposition conditions, e.g. the applied potential. High-resoln. transmission electron microscopy (HRTEM) shows that the av. grain size of NWs increases with increasing Te content. Our results also reveal that the electrodeposited bismuth telluride NWs are n-type, and their elec. cond. increases with increasing Te content. These NWs also demonstrated a max. power factor of 195.8 mW/m·K2 for the Te-rich NW (d = 162 nm) at 300 K. [on SciFinder(R)] Equipe: Département CP2S : Chimie et électrochimie des matériaux |
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Applied Physics Letters,
106(23):233108
2015
Mots clefs: molecular dynamics method phonons thermal conductivity bismuth compounds nanowires Equipe: Département CP2S : Chimie et électrochimie des matériaux |
2014 | |
Articles: | |
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MATERIALS & DESIGN,
56:280-285
2014
ISSN: 0261-3069
Equipe: Département CP2S : Métallurgie et Surfaces |
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Materials & Design,
56:280--285
2014
Equipe: Centre de Compétences : Matériaux et Procédés additifs |
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Journal of Materials Processing Technology,
214(12):3108--3111
2014
Mots clefs: Additive manufacturing, Complex metallic alloys, Icosahedral Al–Cu–Fe–B, Phase transformations Equipe: Centre de Compétences : Matériaux et Procédés additifs |
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JOURNAL OF MATERIALS PROCESSING TECHNOLOGY,
214(12):3108-3111
2014
ISSN: 0924-0136
Equipe: Département CP2S : Métallurgie et Surfaces |
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JOURNAL OF PHYSICAL CHEMISTRY C,
118(40):23032-23041
2014
ISSN: 1932-7447
DOI: 10.1021/jp504906r
Equipe: Département CP2S : Métallurgie et Surfaces |
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Science,
2014
Equipe: Département P2M : Nanomagnétisme et Electronique de Spin |