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1.
Franco Varsano Francesca Decker Enrico Masetti 《Monatshefte für Chemie / Chemical Monthly》2001,132(1):83-95
Summary. Ce-V mixed oxide films have been deposited by RF sputtering with the aim of increasing the Li charge capacity of counter
electrodes in smart windows. Such mixed oxides have shown high transmittance and optical passivity in the visible region.
After electrode pre-conditioning by cyclic voltammetry, a good electrochemical reversibility in LiClO4– propylene carbonate electrolyte was observed, and large Li-charge capacity under galvanostatic charging (up to 50 mCċcm−2) has been measured. The electrode charge capacity decreased after prolonged insertion-deinsertion cycles, whereas the photoptic
transmittance remained about constant. After 800 cycles the Li-charge capacity decreased to 40 mCċcm−2. The Li diffusion coefficient inside the films measured by electrochemical impedance and by galvanostatic titration ranged
from 10−11 cm2ċs−1 to 10−13cm2ċs−1. We observed that the Li charge capacity of the film electrodes is a function of the film deposition conditions, because
it increased with the vanadium oxide concentration in the target and with the oxygen content in the sputtering atmosphere.
Received June 23, 2000. Accepted (revised) August 7, 2000 相似文献
2.
Franco Varsano Francesca Decker Enrico Masetti 《Monatshefte für Chemie / Chemical Monthly》2001,15(2):83-95
Ce-V mixed oxide films have been deposited by RF sputtering with the aim of increasing the Li charge capacity of counter electrodes in smart windows. Such mixed oxides have shown high transmittance and optical passivity in the visible region. After electrode pre-conditioning by cyclic voltammetry, a good electrochemical reversibility in LiClO4– propylene carbonate electrolyte was observed, and large Li-charge capacity under galvanostatic charging (up to 50 mCċcm−2) has been measured. The electrode charge capacity decreased after prolonged insertion-deinsertion cycles, whereas the photoptic transmittance remained about constant. After 800 cycles the Li-charge capacity decreased to 40 mCċcm−2. The Li diffusion coefficient inside the films measured by electrochemical impedance and by galvanostatic titration ranged from 10−11 cm2ċs−1 to 10−13cm2ċs−1. We observed that the Li charge capacity of the film electrodes is a function of the film deposition conditions, because it increased with the vanadium oxide concentration in the target and with the oxygen content in the sputtering atmosphere. 相似文献
3.
本文采用电位阶跃和循环伏安法结合紫外可见光光度法研究了聚苯胺薄膜的电致变色性质. 聚苯胺薄膜颜色多变,颜色在浅黄色到绿色再到蓝色之间变化,本文研究在不同的颜色变化区间内聚苯胺薄膜的电化学循环稳定性. 研究结果表明,薄膜在黄色到蓝色(0.4 V ~ 1.2 V)以及绿色到蓝色(0.8 V ~ 1.2 V)区间变化时,电致变色循环性能较差,而在黄色和绿色(0.4 V ~ 0.8 V)之间变化时循环稳定性能良好,着色时间为4.5 s,着色效率高达159.48 cm2·C-1. 相似文献
4.
Xiao-Yong Fan Fu-Sheng Ke Guo-Zhen Wei Ling Huang Shi-Gang Sun 《Journal of Solid State Electrochemistry》2009,13(12):1849-1858
Sn–Co alloys were electrodeposited on the rough Cu foil and smooth Cu sheet, respectively. The capacity retention of the Sn–Co
alloy electrode electrodeposited on the rough Cu foil in the 70th cycle was found to be 80.0% compared with the maximal capacity,
which was much better than that of the Sn–Co alloy electrode on the smooth Cu sheet. The revolution of the surface morphology
of the Sn–Co alloy electrode during cycling was investigated by scanning electron microscopy. The result indicated that the
reversibility of the expansion and contraction of the Sn–Co alloy electrode on the rough Cu foil during charging/discharging
assisted by the unique rough surface was one main reason of improving the cycleability. Solid electrolyte interphase (SEI)
film was detected on the Sn–Co alloy electrode surface by electrochemical impedance spectroscopy (EIS) during lithiation/delithiation,
and the result demonstrated that the SEI film suffered breaking and repairing at different lithiation status. In addition,
the unique phase transformation process for the Sn–Co alloy electrode during first lithiation was also investigated by EIS. 相似文献
5.
Multilayer thin films containing concanavalin A (Con A) and ferrocene-appended glycogen (FcGly) were prepared by a layer-by-layer
deposition Con A and FcGly by biological affinity (lectin–sugar interaction) on a glassy-carbon electrode. The electrochemical
response of the Con A–FcGly film-coated electrode to sugars was investigated. A cyclic voltammogram (CV), typical of redox
species confined to the surface of the electrode, was obtained. The peak current (resulting from the electric charge involved
in the redox reaction) in the CV from the electrode decreased on addition of sugars in the solution, because the amount of
FcGly on the electrode surface decreased as a result of disintegration of the Con A–FcGly film on addition of sugar. Thus,
d-glucose and other sugars at millimole per liter levels can be detected by use of Con A–FcGly films-coated electrodes. 相似文献
6.
Ahmed Galal Soher A. Darwish Rasha A. Ahmed 《Journal of Solid State Electrochemistry》2007,11(4):521-530
Conducting polymers were deposited on the surface of platinum and glassy carbon electrodes. The monomers used were N-methyl pyrrole and 3-methyl thiophene. The electrochemical synthesis of the polymer was achieved using constant applied potential
or cyclic polarization techniques in acetonitrile as a solvent and tetra-alkyl ammonium salts as supporting electrolyte. The
resulting conducting polymeric film was modified with an inorganic metal complex, namely, Cu–phthalocyanine or Co–phthalocyanine.
Two different approaches were adopted for the modification: (1) the first was to directly apply the metal–phthalocyanine layer
on the surface of the polymer, and (2) the second was by the inclusion of the metal–phthalocyanine in a sol–gel matrix that
was in turn applied to the conducting polymer film. In the first part of this work, we studied the effect of changing the
type of polymer matrix and the central metal of the inorganic complex on the electrochemical behavior of the resulting film.
We also found that changing the method of metal–phthalocyanine application to the polymer film affected the electrochemical
response and kinetics at the electrode surface. The new electrode was tested for the reduction of hydrogen peroxide and showed
better conversion efficiency compared to conventional surfaces, which suggests its use in fuel cell applications. 相似文献
7.
Single-wall carbon nanotube (SWNT) is processed in three different ways: (1) coating a film out of a slurry of SWNT with poly
(vinilydene difluoride) (PVDF) binder on to a Cu substrate, (2) evaporating SWNT dispersion in methanol on to a Cu substrate,
and (3) transferring a film on to a Cu substrate from the water–ethanol interface, to prepare the working electrode for studying
the Li ion insertion process. The use of binder enhances irreversible capacity restricting the Coulomb efficiency to only
18% in the initial cycle. The electrode prepared by deposition of SWNT powder from a dispersion of methanol on the Cu substrate
gives the best reversible capacity of 445 mA h g−1 and Coulomb efficiency of 25% in the initial cycle. Use of the PVDF binder favors the formation of thicker solid electrolyte
interface, which counts the large irreversible capacity. 相似文献
8.
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
9.
Prasanta Kumar Biswas 《Journal of Sol-Gel Science and Technology》2011,59(3):456-474
Thin films have wide applications in the area of optics and photonics. Conventional thin film processing is usually followed
for deposition, but the sol–gel route is unique as it can be applied very easily in a cost effective way on desired substrates
of any shape for specific applications. In this review, the basic optical designs of antireflection, high reflection, different
types of optical filters, coloured coatings, etc. have been discussed with some typical examples of sol–gel products. The
importance of coloured coatings and low thermal emissivity coatings on window glass has also been highlighted. In addition,
the use of sol–gel processing for different types of film formation which are effective for photonic applications such as
non-linearity in optics, ferromagnetism in transparent dilute magnetic semiconductors (DMS), generation of quantum dots as
phosphor, grating coupler waveguide in optical sensors are discussed. The basic characterizations of a few sol–gel products
which may be used for photonic applications have also been highlighted. 相似文献
10.
Ahmed Galal 《Journal of Solid State Electrochemistry》1998,2(1):7-15
Conducting poly(3-methylthiophene) electrodes were electrochemically prepared. The resulting polymer films were modified
with an inorganic complex, ferrocene. The incorporation of the ferrocene/ferrocenium moiety into the polymer film resulted
in enhanced charge transfer towards the oxidation of some organic molecules of biological interest. The electrochemical response
of the complex-containing polymer electrode was compared to that of the unmodified polymer electrode and that of the substrate.
Apparent diffusion coefficients of the redox species were estimated from the cyclic voltammetric data for different biological
molecules at the ferrocene-containing polymer electrode. Infra-red spectroscopic measurements for the “as-grown” films revealed
the presence of the inorganic complex within the polymer. The modified polymer electrode showed noticeable enhancement for
the charge transfer across the film interface and can be used as an electrochemical sensor for biological compounds.
Received: 3 June 1997 / Accepted: 7 July 1997 相似文献
11.
After being treated by mixed acids, single-walled carbon nanotubes (SWNTs) were shortened and had negatively charged groups
on the surface. Positively charged hemoglobin or myoglobin at pH 5.0 was successfully assembled with SWNTs into layer-by-layer
films on solid surfaces, designated as {SWNT/protein}
n
. While only those proteins in the first few bilayers closest to the electrode surface exhibited electroactivity, the {SWNT/protein}
n
films demonstrated a much higher fraction of electroactive proteins and better controllability in film construction compared
with cast films of the proteins and carbon nanotubes. The proteins in the {SWNT/protein}
n
films retained their near-native structure at medium pH. The stable protein film electrode showed good electrocatalytic properties
toward reduction of oxygen and hydrogen peroxide, demonstrating the potential application of the {SWNT/protein}
n
films as a new type of biosensor based on the direct electrochemistry of proteins without using mediators.
Figure Cyclic voltammograms at 0.2 V s−1 in pH 7.0 buffers with different number of bilayers (n) for layer-by-layer {single-walled carbon nanotube/hemoglobin}
n
films. 相似文献
12.
The method of flow injection into the gas flow with detection of current resistance of the film was used to investigate the
action of ammonia and water vapor on neodymium diphthalocyanine film. The value and sign of the electrophysical response are
reversible at 18–22°C. When the film contacts with vapor, the current is changed within a few seconds, whereas the relaxation
to the initial value when vapor is removed occurs within tens of seconds. The response parameters are suitable for developing
effective sensors based on resistant films. No optical changes in the absorption spectra of the films were observed in the
400–800 nm region under the action of ammonia and water vapor.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1446–1447, July, 1998. 相似文献
13.
A. A. Mikhaylova E. K. Tusseeva A. Yu. Rychagov Yu. M. Vol’fkovich A. V. Krestinin O. A. Khazova 《Russian Journal of Electrochemistry》2010,46(11):1280-1288
Composites of functionalized single-wall carbon nanotubes and polyaniline are deposited onto electrodes by in situ electrochemical
polymerization. Their electrochemical behavior and differential capacitance are studied by cyclic voltammetry, electrochemical
impedance spectroscopy, and chronovoltamperometry. The differential capacitance of the composite electrode exceeds that of
pure polyaniline film deposited onto electrode, which can be explained by the nanotubes’ loosening effect on the polyaniline
structure. The composite-electrode capacitance is as large as 1000 F g−1 or higher. Thus obtained composite films were used as a support for deposited platinum-ruthenium catalyst. The Pt-Ru structure
and catalytic properties in the methanol oxidation reaction are studied. It is shown that the specific current of methanol
oxidation at Pt-Ru is larger by a factor of 7–15 than those measured when pure polyaniline, pure carbon nanotubes, or standard
Vulcan XC-72 carbon black are used as supports. It is found that the catalytic activity is the same for all studied supports,
provided the current is reduced to the unit of Pt-Ru true surface area. Thus, the observed large catalytic effect is associated
with the structure and high dispersivity of the electrodeposited metals incorporated to the single-wall carbon nanotubes-polyaniline
composite. 相似文献
14.
Jing-Jing Yu Shuang Lu Jiang-Wen Li Fa-Qiong Zhao Bai-Zhao Zeng 《Journal of Solid State Electrochemistry》2007,11(9):1211-1219
This study reports the preparation and characterization of gold nanoparticles deposited on amine-functioned hexagonal mesoporous
silica (NH2–HSM) films and the electrocatalytic oxidation of glucose. Gold nanoparticles are fabricated by electrochemically reducing
chloroauric acid on the surface of NH2–HSM film, using potential step technology. The gold nanoparticles deposited have an average diameter of 80 nm and show high
electroactivity. Prussian blue film can form easily on them while cycling the potential between −0.2 and 0.6 V (vs saturated
calomel electrode) in single ferricyanide solution. The gold nanoparticles loading NH2–HSM-film-coated glassy carbon electrode (Au–NH2–HSM/GCE) shows strong catalysis to the oxidation of glucose, and according to the cathodic oxidation peak at about 0.16 V,
the catalytic current is about 2.5 μA mM−1. Under optimized conditions, the peak current of the cathodic oxidation peak is linear to the concentration of glucose in
the range of 0.2 to 70 mM. The detection limit is estimated to be 0.1 mM. In addition, some electrochemical parameters about
glucose oxidation are estimated. 相似文献
15.
Kim SK Lee H Tanaka H Weiss PS 《Langmuir : the ACS journal of surfaces and colloids》2008,24(22):12936-12942
Films of chemically shortened and functionalized single-walled carbon nanotubes (SWNTs) have been formed on a gold electrode by electrophoretic deposition. Applying ultrasonic energy resulted in dramatic changes of the film morphology; the deposited SWNT bundles reassembled and oriented normal to the electrode. Oriented SWNT bundles with high density (more than 250 bundles/microm (2)) not only presented narrow size distributions, but uniformly spread on the electrode. We discuss the mechanism of SWNT orientation by analyzing the variation in the film morphology with ultrasonication time. In addition, we suggest that the 3D displays of AFM images can lead to misjudgment of nanotube alignment. The method for aligning SWNTs normal to the electrode may be competitive with chemical vapor deposition or screen printing, the predominant methods by which vertically aligned SWNT films have been fabricated to date. 相似文献
16.
Obtaining uniformly dispersed SWNT within an aqueous mixture for subsequent use as a dried coating in electronic biosensors is a challenge. The objective of this study is to relate SWNT dispersion conditions to resultant dried film properties. Aqueous solutions of SWNT dispersed with CMC (a dispersing agent with unique properties compatible with biomolecules) at different SWNT:CMC weight ratios and at different sonication conditions were studied. Solution particle size distribution data was obtained using dynamic light scattering. Differently formulated/processed SWNT/CMC solutions were used to form dry thin, conductive films. The resistance of each film was measured and its resistivity calculated. Response Surface Methodology (RSM) design of experiments (DOE) analysis was used as the tool to fit the data to establish a model and identify trends for the parameters studied. Profilometry was used to examine film surface uniformity. 3D optical microscopy was used to investigate film morphology and determine film thickness, and to relate these data back to solution dispersion conditions and dried film resistances. The lowest dried film resistivity (0.012 ohm-cm) was obtained at the highest levels of parameters studied in the DOE. Smaller solution particle size resulted in lower dried film surface roughness and better film uniformity. 相似文献
17.
Luis A. Toledo-Matos Maximo Antonio Pech-Canul 《Journal of Solid State Electrochemistry》2011,15(9):1927-1934
The evolution under open-circuit conditions of iron passive films formed at 0.8 VSCE in a borate buffer solution at pH 8.4 was investigated with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry.
The composition of the freshly formed passive film as determined by X-ray photoelectron spectroscopy (XPS) was found to be
in agreement with a bilayer model, where the inner layer is composed mainly of iron oxide and the outer layer consists of
a hydrated material. Results of XPS measurements also showed that the open-circuit breakdown of passive films was consistent
with a reductive dissolution mechanism. When the iron electrode reached an intermediate stage in the open-circuit potential
decay (approximately −0.3 VSCE), the oxide film, containing both Fe(II) and Fe(III), was still protective. The impedance response in this stage exhibited
a mixed control by charge transfer at the metal/film and film/solution interfaces and diffusion of point defects through the
film. At the final stage of the open-circuit potential decay (approximately −0.7 VSCE), the oxide film was very thin, and the ratio of Fe3+/Fe2+ and O2−/OH− had decreased significantly. The impedance response also exhibited a mixed charge-transfer–diffusion control, but the diffusion
process was related to transport of species in the electrolyte solution resulting from dissolution of the oxide film. 相似文献
18.
羧基化单层碳纳米管修饰电极的电化学表征及其电催化作用 总被引:52,自引:3,他引:49
碳纳米管自 1 991年被发现 [1] 以来 ,因其独特的力学、电子特性及化学稳定性 ,成为世界范围内的研究热点之一 .它可以认为是将石墨层折叠成碳圆柱体的结果 ,分为多层碳纳米管 ( MWNT)和单层碳纳米管 ( SWNT) .依据其原子结构不同 ,碳纳米管将表现为金属或半导体 ,这种独特的电子特性使它有望成为新型分子器件 .因此 ,研究这种新型碳结构的电极特性具有十分重要的意义 .MWNT与溴仿等混合后装在玻璃毛细管内制成微电极 ,可用于探测生物电化学反应 ,结果明显优于其它碳电极 [2 ,3] .对 SWNT的电化学行为研究得较少 .目前仅有一篇有关 S… 相似文献
19.
以单壁碳纳米管作为电极材料,基于减压过滤和电聚合方法制备了一种薄膜型一氧化氮(NO)电化学传感器。扫描电镜、红外光谱和电化学交流阻抗表征表明,减压过滤可以制备出导电性好、电分析性能优良的薄膜电极,而罗丹明B能通过电聚合在其表面形成高比表面的纳米敏感结构。这种薄膜型电化学传感器对NO具有灵敏的电化学响应,其安培氧化电流与NO浓度在7.2×10-8~2.5×10-5mol/L范围内呈良好的线性关系,检出限(S/N=3)达3.6×10-8mol/L。将该传感器紧贴在麻醉豚鼠的肝脏表面,成功实现了肝组织细胞在L-精氨酸刺激下NO释放的实时监测。 相似文献
20.
Yan Cheng Guan Wang Manming Yan Zhiyu Jiang 《Journal of Solid State Electrochemistry》2007,11(2):310-316
The interfacial properties of mesocarbon-microbeads (MCMB) and lithium electrodes during charge process in poly (vinylidenefluoride-co-hexafluoropropylene)-based gel electrolyte were investigated by in situ Raman microscopy, in situ Fourier transform-infrared (FTIR) spectroscopic methods, and charge–discharge, electrochemical impedance spectroscopy techniques. For MCMB electrode, the series phase transitions from initial formation of the dilute stage 1 graphite intercalation compound (GIC) to a stage 4 GIC, then through a stage 3 to stage 2, and finally to stage 1 GIC was proved by in situ Raman spectroscopic measurement. The formation of solid electrolyte interface (SEI) films formed on MCMB and metal lithium electrode was studied by in situ reflectance FTIR spectroscopic method. At MCMB electrode surface, the solvent (mostly ethylene carbonate) decomposed during charging process and ROCO2Li may be the product. ROCO2Li, ROLi, and Li2CO3 were the main composites of SEI film formed on lithium electrode, not on electrodeposited lithium electrode or lithium foil electrode. 相似文献