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1.
Carbon materials enriched with nitrogen and oxygen surface functional groups were obtained by pyrolyzing strained beer yeast
at 750 °C under an inert atmosphere. Physical and surface properties of the carbon obtained were characterized by X-ray powder
diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, Raman spectrometry, and X-ray
photoelectron spectroscopy. Results show that the carbon possesses an amorphous structure, a spherical morphology, and a high
density of surface functional groups. Electrochemical properties were evaluated by cyclic voltammetry, a galvanostatic charge–discharge
technique, and electrochemical impedance spectroscopy. The carbon has 989.65 mAh·g−1 of initial discharge capacity and a stable cycle performance for a Li–C cell. A specific capacitance of 120 F·g−1 was obtained for a single carbon electrode and good cycle performance was achieved for a symmetrical supercapacitor fabricated
using this carbon. These carbons derived from strained beer yeast have promising applications in energy storage and conversion
systems. 相似文献
2.
Platinum nanoparticles were successfully deposited within a multiwalled carbon nanotube (MWCNT)–Nafion matrix by a cyclic
voltammetry method. A Pt(IV) complex was reduced to platinum nanoparticles on the surface of MWCNTs. The resulting Pt nanoparticles
were characterized by scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy.
The Pt–MWCNT–Nafion nanocomposite film-modified glassy carbon electrode had a sharp hydrogen desorption peak at about −0.2 V
vs. Ag/AgCl (3 M) in a solution of 0.5 M H2SO4, which is directly related to the electrochemical activity of the Pt nanoparticles presented on the surface of MWCNTs. The
electrocatalytic properties of the Pt–MWCNT–Nafion nanocomposite-modified glassy carbon electrode for methanol electrooxidation
were investigated by cyclic voltammetry in a 2 M CH3OH + 1 M H2SO4 solution. In comparison with the Pt-coated glassy carbon electrode and the Pt–Nafion modified glassy carbon electrode, the
Pt–MWCNT–Nafion-modified electrode had excellent electrocatalytic activity toward methanol electrooxidation. The stability
of the Pt–MWCNT–Nafion nanocomposite-modified electrode had also been evaluated. 相似文献
3.
Zhan Lin Liwen Ji Andrew J. Medford Quan Shi Wendy E. Krause Xiangwu Zhang 《Journal of Solid State Electrochemistry》2011,15(6):1287-1294
The growing demands for reagentless hydrogen peroxide (H2O2) and β-nicotinamide adenine dinucleotide (β-NADH) sensors from food, pharmaceutical, chemical, and biochemical fields have
stimulated extensive research interest on nano-engineered Pd. In this paper, Pd/carbon composite nanofibers were prepared
by electrodepositing Pd onto electrospun carbon nanofibers to act as a catalyst toward the electrocatalytic redox reactions
of H2O2 and β-NADH. The morphology of nano-engineered Pd was controlled by selectively adjusting the electrodeposition time and potential.
Scanning electron microscopy and transmission electron microscopy results showed that nanocactus- and nanoflower-like Pd depositions
were obtained on the surface of carbon nanofibers. Electrocatalytic analysis demonstrated a high electrocatalytic activity
of the composite nanofibers for the redox of H2O2 and oxidation of β-NADH. 相似文献
4.
V. A. Khavrus’ N. V. Lemesh S. V. Gordeichuk A. I. Tripol’skii T. S. Ivashchenko P. E. Strizhak 《Theoretical and Experimental Chemistry》2006,42(4):234-238
Multiwalled carbon nanotubes were synthesized catalytically from ethylene in the presence of water vapor at transition metals
of the iron subgroup. The structure of the obtained nanotubes was studied by transmission electron microscopy, high-resolution
transmission electron microscopy, and Raman spectroscopy. It was shown that the highest yields of carbon nanotubes with diameters
between 20 and 40 nm, lengths of more than 1 μm, and average diameter of 0.92 nm for the innermost tube were obtained at a
nickel catalyst with a water vapor concentration of 0.32%.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 4, pp. 227–230, July–August, 2006. 相似文献
5.
Nanocrystalline nickel with an average diameter of about 16 nm and a face-centered cubic (fcc) structure was uniformly attached
to the surface of carbon nanotubes (CNT) by wet chemistry. The sample was characterized by X-ray powder diffraction and transmission
electron microscopy (TEM). A glass carbon electrode modified with nickel-modified multi-wall carbon nanotubes (MWCNTs-Ni/GCE)
was prepared. The electrochemical behavior of the MWCNTs-Ni/GCE and the electrocatalytic oxidation of methanol at the MWCNTs-Ni/GCE
were investigated by cyclic voltammetry in 1.0 mol/L NaOH solution. The cyclic voltammograms showed that the electron transfer
between β-Ni(OH)2 and β-NiOOH is mainly a diffusion-controlled quasireversible process, and that the electrode has high catalytic activity for the
electrooxidation of methanol in alkaline medium, revealing its potential application in alkaline rechargeable batteries and
fuel cells.
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Translated from Chinese Journal of Applied Chemistry, 2007, 24(5): 503–506 [译自: 应用化学] 相似文献
6.
Boyang Liu Dechang Jia Jiancun Rao Pengjian Zuo Yingfeng Shao 《Journal of Solid State Electrochemistry》2009,13(3):497-501
Hollow carbon microspheres (HCMs) are prepared in a sealed quartz tube via the reaction between ferrocene and ammonium bromide.
The morphology and microstructure of the product are characterized by X-ray diffraction, Raman spectroscopy, scanning electron
microscopy, focused ion beam workstation, transmission electron microscopy, and differential scanning calorimetry analysis.
The diameter of the HCMs ranges from 1 to 13 μm and the thickness of shells ranges from 70 nm to 450 nm. It is concluded that
the self-generated spherical droplets of iron amine bromide serve as the core templates for the formation of HCMs. 相似文献
7.
Zonghui Yi Xiaoyan Han Changchun Ai Yongguang Liang Jutang Sun 《Journal of Solid State Electrochemistry》2008,12(9):1061-1066
The electrochemical properties of the 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA)-based carbon, synthesized by directly
pyrolyzing PTCDA under an argon gas flow, have been firstly explored as an anode material for lithium-ion batteries. PTCDA
is decomposed in a single-step reaction, which was completed around 650 °C. X-ray diffraction studies indicated a disordered
carbon structure, and scanning electron microscopy (SEM) results revealed that this PTCDA-based carbon had a pillar-like morphology
with a diameter of approximately 1–4 μm and length of 5–20 μm. Electrochemical measurements showed that it delivered lithium
insertion and deinsertion capacities of 496 and 311 mAh g−1, respectively, during the first cycle. The charge capacity retention from the 1st to the 50th is 93.2% with an average capacity
fade of 0.14% per cycle. The coulombic efficiency of the Li insertion/deinsertion processes reached 99% after five cycles. 相似文献
8.
Shi-Wei Wang Wei Yang Rui-Ying Bao Ben Wang Bang-Hu Xie Ming-Bo Yang 《Colloid and polymer science》2010,288(6):681-688
A kind of β-nucleating agent, calcium pimelate, for polypropylene (PP) was chemically supported onto the surface of multi-wall
carbon nanotubes, and the effect of the multi-wall carbon nanotube-supported β-nucleating agent on the mechanical properties
and morphology of isotactic polypropylene composites was investigated. The composites of isotactic polypropylene and multi-wall
carbon nanotube-supported β-nucleating agent exhibited excellent impact toughness compared with pure isotactic polypropylene
and β-nucleated isotactic polypropylene, being more than seven times over that of pure isotactic polypropylene and more than
three times over that of β-nucleated isotactic polypropylene. The excellent impact behaviors of the composites were also evidenced
by the fracture morphology based on scanning electron microscopy observations. Differential scanning calorimetry and wide-angle
X-ray diffraction results verified the enhanced nucleating ability of the multi-wall carbon nanotube-supported β-nucleating
agent, which greatly improved the impact toughness without significantly deteriorating the strength and stiffness of the polypropylene
composites. 相似文献
9.
Stefan Kuypers 《Mikrochimica acta》2002,138(3-4):235-247
The possibilities and limitations of electron probe microanalysis and scanning electron microscopy at reduced accelerating
voltages are summarised. The application of electron probe microanalysis to the analysis of thin coatings in the boron–nitrogen–carbon
composition triangle is discussed. Experimental details are given. The potential of modern scanning electron microscopes,
operated at low voltages and high magnifications, for materials development and problem solving is illustrated. Examples shown
are from fluorocarbon coatings, ultrafiltration membranes, membrane fouling and casings for meat. Experimental details are
given. 相似文献
10.
Zhongxue Chen Yuliang Cao Jiangfeng Qian Xinping Ai Hanxi Yang 《Journal of Solid State Electrochemistry》2012,16(1):291-295
A sandwiched SiC@Pb@C nanocomposite was prepared through a simple ball-milling route and characterized by X-ray diffraction,
X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The SiC@Pb@C nanocomposite
exhibits a much improved reversible capacity and cycling life as compared with a bare Pb anode. A reversible volumetric capacity
of >1,586 mAh cm−3 (207 mAh g−1) can be maintained after 600 cycles of charge and discharge in the potential interval between 0.005 and 1.0 V, which far
exceeds those reported previously in the literature. The enhanced electrochemical performance is ascribed to the sandwiched
structure in which nanosized Pb particles were anchored in between the rigid SiC core and the outer carbon shell, mitigating
the damage done by the large volume change of the Pb interlayer during the alloying/dealloying process. 相似文献
11.
The influence of asymmetric catalytic particles prepared by various methods was investigated on the growth of spiral carbon
nanotubes using the CVD method. Asymmetric particles were prepared by either milling or crystallization from oversaturated
solution onto the surface of catalyst support or catalyst impregnation at pH 8–9. As-prepared catalysts were tested in the
decomposition of acetylene. Carbon deposit, thus carbon nanotubes and spirals were observed by transmission electron microscopy
the activity was characterized by carbon yield. 相似文献
12.
Stuart M. Macdonald Katarzyna Szot Joanna Niedziolka Frank Marken Marcin Opallo 《Journal of Solid State Electrochemistry》2008,12(3):287-293
A hydrophilic carbon nanoparticle–sol-gel electrode with good electrical conductivity within the sol-gel matrix is prepared.
Sulfonated carbon nanoparticles with high hydrophilicity and of 10–20 nm diameter (Emperor 2000) are co-deposited onto tin-doped
indium oxide substrates employing a sol-gel technique. The resulting carbon nanoparticle-sol-gel composite electrodes are
characterized as a function of composition and salt (KCl) additive. Scanning electron microscopy and voltammetry in the absence
and in the presence of a solution redox system suggest that the composite electrode films can be made electrically conducting
and highly porous to promote electron transport and transfer. The effect of the presence of hydrophilic carbon nanoparticles
is explored for the following processes: (1) double layer charging, (2) diffusion and adsorption of the electrochemically
reversible solution redox system 1,1′-ferrocenedimethanol, (3) electron transfer to the electrochemically irreversible redox
system hydrogen peroxide, and (4) electron transfer to the redox liquid tert-butylferrocene deposited into the porous composite
electrode film. The extended electrochemically active hydrophilic surface area is beneficial in particular for surface sensitive
processes (1) and (3), and it provides an extended solid|organic liquid|aqueous solution boundary for reaction (4). The carbon
nanoparticle–sol-gel composite electrodes are optimized to provide good electrical conductivity and to remain stable during
electrochemical investigation. 相似文献
13.
Angelina Sarapulova Daria Mikhailova Ljubomira Ana Schmitt Steffen Oswald Natalia Bramnik Helmut Ehrenberg 《Journal of Sol-Gel Science and Technology》2012,62(1):98-110
LiCoPO4-coated disordered carbon nanofibers (CNFs/LiCoPO4) were obtained by a sol–gel method, using triethyl phosphite or triethyl phosphate as the phosphorous source. The crystal
structure of the products was analyzed by X-ray powder diffraction, while morphology was studied using scanning electron microscopy,
transmission electron microscopy, Auger electron spectroscopy and X-ray photoelectron spectroscopy. Optimal synthesis conditions
for the CNFs/LiCoPO4 in light of the best electrochemical performance are discussed. The best discharge capacity 105 mAh/g (or ca. 63% of the
theoretical capacity) shows the material with 40% CNFs/LiCoPO4 and addition coating by carbon black. This composition has a best purity of active materials and point coverage of CNFs.
The X-ray photoelectron C1s spectra of the CNFs surface without and with sputter erosion show enhancement of C–O bonds at
the fiber surface, which does not influence significantly electrochemical behavior of the composite materials. 相似文献
14.
Galyna Shul Maria A. Murphy Geoff D. Wilcox Frank Marken Marcin Opallo 《Journal of Solid State Electrochemistry》2005,9(12):874-881
Composite electrodes were prepared from chemical vapor deposition grown carbon nanofibers consisting predominantly of ca.
100 nm diameter fibers. A hydrophobic sol–gel matrix based on a methyl-trimethoxysilane precursor was employed and composites
formed with carbon nanofiber or carbon nanofiber—carbon particle mixtures (carbon ceramic electrode). Scanning electron microscopy
images and electrochemical measurements show that the composite materials exhibit high surface area with some degree of electrolyte
solution penetration into the electrode. These electrodes were modified with redox probe solution in 2-nitrophenyloctylether.
A second type of composite electrode was prepared by simple pasting of carbon nanofibers and the same solution (carbon paste
electrode). For both types of electrodes it is shown that high surface area carbon nanofibers dominate the electrode process
and enhance voltammetric currents for the transfer of anions at liquid|liquid phase boundaries presumably by extending the
triple-phase boundary. Both anion insertion and cation expulsion processes were observed driven by the electro-oxidation of
decamethylferrocene within the organic phase. A stronger current response is observed for the more hydrophobic anions like
ClO4− or PF6− when compared to that for the more hydrophilic anions like F− and SO42−.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
15.
Junping Dong Yanyan Hu Shenmin Zhu Jiaqiang Xu Yinjuan Xu 《Analytical and bioanalytical chemistry》2010,396(5):1755-1762
An ordered mesoporous carbon material functionalized with carboxylic acid groups was synthesized. It was characterized by
powder X-ray diffraction, transmission electron microscopy, Fourier transform IR spectroscopy and N2 adsorption/desorption. Furthermore, this material was used to modify an electrode surface combined with a hydrophobic ionic
liquid. The functionalized ordered mesoporous carbon/ionic liquid gel modified electrode shows excellent electrocatalytic
performances for the oxidation of dopamine, uric acid and ascorbic acid. The presence of the ionic liquid promotes the electron
transfer. Linear responses for dopamine and uric acid were obtained in the ranges of 0.1 to 500 μM and from 0.1 to 100 μM
with detection limits of 4.1 and 2.5 nM (signal-to-noise ratio of 3), respectively, under optimum conditions. A quick and
sensitive biosensor based on functionalized ordered mesoporous carbon and an ionic liquid has been developed for the first
time for the detection of dopamine and uric acid in the presence of a large amount of ascorbic acid. 相似文献
16.
Caixian Chang Jiangfeng Xiang Ming Li Xiaoyan Han Liangjie Yuan Jutang Sun 《Journal of Solid State Electrochemistry》2009,13(3):427-431
A sulfur-substituted disordered carbon is explored as anode material for lithium-ion battery. Its physical and electrochemical
properties are characterized by a variety of techniques such as powder X-ray diffraction, element analysis, Fourier transform
infrared spectrum, scanning electron microscopy, and typical electrochemical tests. Electrochemical tests show the activated
carbon displays a first cycle discharge capacity of 1,216 mAh·g−1. It also has a remarkable cycling stability with an average capacity fade of 0.92% per cycle from 11th to 100th cycle in
the range of 0.01–3.00 V versus metallic lithium at a current density of 100 mA·g−1. After 100 cycles, the electrode still maintained a capacity of 420 mAh·g−1. 相似文献
17.
P. Lavela F. Nacimiento G. F. Ortiz J. L. Tirado 《Journal of Solid State Electrochemistry》2010,14(1):139-148
Sn–Co–C composites have been prepared by using the resorcinol/formaldehyde polymerization method combined with the carbothermal
reduction of metal oxides during carbonization. Homogeneously dispersed metal/carbon composites were identified by electron
microscopy. Scanning electron microscopy images revealed the presence of carbonaceous particles with inclusions of metal agglomerates,
and the X-ray diffraction patterns revealed the presence of tin and cobalt–tin phases. The introduction of small amounts of
cobalt led to higher capacities as compared to coke and cobalt-free samples. The sample with a Sn/Co molar ratio of 85:15
and a higher, initial metal oxide-to-resorcinol ratio was able to maintain capacity values near 380 mAh/g after 30 cycles.
The instability of cobalt–tin phases on cycling was not a hindrance for the electrochemical behavior. Charge transfer resistance
values were kept low during cycling for cobalt-containing composites. 相似文献
18.
以惰性盐KCl为模板、硝酸镍为金属催化剂镍源、葡萄糖为碳源,通过碳化处理制备了介孔石墨化碳片。利用扫描电子显微镜、透射电子显微镜、X-射线衍射仪和比表面测试仪对介孔石墨化碳片进行了表征。探讨了碳片形成的机理,采用三电极测试体系研究了介孔石墨化碳片电极材料的电化学性能。结果表明,10 g KCl制备的碳片比表面积最大(989 m2·g-1),在6 mol·L-1KOH电解液中,当电流密度为0.5 A·g-1时,比电容达到180 F·g-1;当电流密度达到10 A·g-1时,比电容维持在148 F·g-1,显示了电极具有较好的倍率性能;在10 A·g-1条件下,2 000次循环充放电测试后电容没有发生衰减,展示了在超级电容器方面的应用潜力。 相似文献
19.
以惰性盐KCl为模板、硝酸镍为金属催化剂镍源、葡萄糖为碳源,通过碳化处理制备了介孔石墨化碳片。利用扫描电子显微镜、透射电子显微镜、X-射线衍射仪和比表面测试仪对介孔石墨化碳片进行了表征。探讨了碳片形成的机理,采用三电极测试体系研究了介孔石墨化碳片电极材料的电化学性能。结果表明,10gKCl制备的碳片比表面积最大(989m2·g-1),在6mol·L-1KOH电解液中,当电流密度为0.5A·g-1时,比电容达到180F·g-1;当电流密度达到10A·g-1时,比电容维持在148F·g-1,显示了电极具有较好的倍率性能;在10A·g-1条件下,2000次循环充放电测试后电容没有发生衰减,展示了在超级电容器方面的应用潜力。 相似文献
20.
Ru oxide/carbon fabric composites (Ru oxide/CF) were prepared by impregnating carbon fabric (CF) with a hydrous RuO2 suspension. Their properties were characterized by scanning electron microscopy, impedance spectroscopy, cyclic voltammetry,
and constant current discharging. Specific capacitance increased with increasing loading of Ru oxide. The apparent average
specific capacitance of the Ru oxide component reached 1,085 F g−1 for a 9.15% loading, with a peak of 1,984 F g−1 at approximately 0.3 V vs Ag/AgCl. The presence of Ru oxide decreases the ionic resistance of the CF and appears to increase
its specific capacitance by generating additional electroactive surface functionality. 相似文献