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1.
Shen-Ming Chen Wen-Yan Chzo R. Thangamuthu 《Journal of Solid State Electrochemistry》2008,12(11):1487-1495
Electrochemically active hybrid coatings based on cationic films, didodecyldimethylammonium bromide (DDAB), and poly(diallyldimethylammonium
chloride) (PDDAC) are prepared on electrode surface by cycling the film-covered electrode repetitively in a pH 6.5 solution
containing Fe(CN)6
3− and Ru(CN)6
4− anions. Modified electrodes exhibited stable and reversible voltammetric responses corresponding to characteristics of Fe(CN)6
3−/4− and Ru(CN)6
4−/3− redox couples. The cyclic voltammetric features of hybrid coatings resemble that of electron transfer process of surface-confined
redox couple. Electrochemical quartz crystal microbalance results show that more amounts of electroactive anionic complexes
partitioned into DDAB coating than those doped into PDDAC coating from the same doping solution. Peak potentials of hybrid
film-bound redox couples showed a negative shift compared to those at bare electrode and this shift was more pronounced in
the case of DDAB. Finally, the advantages of hybrid coatings in electrocatalysis are demonstrated with sulfur oxoanions. 相似文献
2.
Functionalized polypyrrole films were prepared by incorporation of Fe(CN)6
3− as doping anion during the electropolymerization of pyrrole at a glassy carbon electrode from aqueous solution. The electrochemical
behavior of the Fe(CN)6
3−/Fe(CN)6
4− redox couple in polypyrrole was studied by cyclic voltammetry. An obvious surface redox reaction was observed and dependence
of this reaction on the solution pH was illustrated. The electrocatalytic ability of polypyrrole film with ferrocyanide incorporated
was demonstrated by oxidation of ascorbic acid at the optimized pH of 4 in a glycine buffer. The catalytic effect for mediated
oxidation of ascorbic acid was 300 mV and the bimolecular rate constant determined for surface coverage of 4.5 × 10−8 M cm−2 using rotating disk electrode voltammetry was 86 M−1 s−1. Furthermore, the catalytic oxidation current was linearly dependent on ascorbic acid concentration in the range 5 × 10−4–1.6 × 10−2 M with a correlation coefficient of 0.996. The plot of i
p versus v
1/2 confirms the diffusion nature of the peak current i
p.
Received: 12 April 1999 / Accepted: 25 May 1999 相似文献
3.
The remarkable enhancement of electron transfer on screen-printed carbon electrodes (SPCEs) with modification by iron nanoparticles
(Fenano), coupled with Fe(CN)6
4−/3− redox species, was characterized with an increase of electroactive area (A
ea) at electrode surface together with a decrease of heterogeneous electron transfer rate constant (k°) in the system. Hence, Fenano-Fe(CN)6
3− SPCEs with deposition of glucose oxidase (GOD) demonstrated a higher sensitivity to various glucose concentrations than Fe(CN)6
3−/GOD-deposited SPCEs. In addition, an inhibited diffusion current from cyclic voltammograms was also observed with an increase
in redox concentration and complicated the estimation of A
ea. Further analysis by the electrochemical impedance method, it was shown that this effect might be resulted from the electrode
surface blocking by the products of activated complex decomposition. 相似文献
4.
A. G. Zelinskii 《Russian Journal of Electrochemistry》2010,46(4):431-437
Variations in the current in the [Fe(CN)6]3−/[Fe(CN)6]4− system flowing through a vertical microorifice in the insulating film on the electrode are shown. Steady- and nonsteady-state
conditions of electrolysis are studied for different insulating film thicknesses. The obtained results suggest that at steady-state
electrolysis, in an insulator channel, near the electrode, a “stagnant zone” is formed in which the natural convection of
electrolyte is weak. Mass transfer in this zone preferentially occurs due to the reagent diffusion. The length of this zone
increases with the increase in the channel length. A zone with the natural convection of electrolyte is located at a certain
distance from the electrode, closer to the insulator surface. A part of this zone is located in the solution bulk and its
thickness is independent of the channel length. The mass transfer in this zone is realized by both the reagent diffusion and
the natural convection of electrolyte. Voltammetric measurements show that at sufficiently high potential scanning rates,
the peak currents on a planar electrode and on an electrode placed on the bottom of the channel in the insulating film virtually
coincide. This result points to the possibility of using potentiodynamic methods for analyzing the electrolyte composition
inside the channel and in the solution bulk irrespective of the thickness of the electrode-insulating film. 相似文献
5.
Photoelectrochemical corrosion of n-type α-PbO electrodes in aqueous Fe(CN)6
3−/4− and I−/I3
− electrolytes using the rotating ring-disk electrode technique has been investigated. The α-PbO thin film is found to be more
stable in I−/I3
− (48%) than in Fe(CN)6
3−/4− electrolyte (10%). Preferential adsorption of iodide ions decreases the photocorrosion reaction of holes with α-PbO. Addition
of CsI (0.4 mM) to the I−/I3
− electrolyte decreases the photocorrosion from 48% to less than 10%. Cs+ ions perhaps nullify the effect of negatively charged surface states of α-PbO, thus minimizing the trapping of holes at the
surface of α-PbO and hence decrease the possibility of photocorrosion of lead oxide with holes.
Received: 30 June 1998 / Accepted: 20 April 1999 相似文献
6.
Nitrogenated nanocrystalline diamond films with controlled electrical conductivity are grown in electrical arc plasma in CH4/H2/Ar/N2 gas mixtures and characterized by scanning electron microscopy and spectroscopic measurements. Their electrochemical properties
are studied by electrochemical impedance spectroscopy. Transfer coefficients of reactions in the [Fe(CN)6]3−/4− redox system are determined. The electrochemical behavior of the material is controlled by its nitrogenation (3–20% N2 in the reaction gas mixture). The nitrogenated nanocrystalline diamond has higher differential capacitance in indifferent
electrolyte (1 M KCl) solution than not nitrogenated one; the nitrogenation also increases the reversibility of reactions
in the [Fe(CN)6]3−/4− redox system. By and large, with nitrogenation of diamond, its electrochemical behavior changes from the one characteristic
of a “poor conductor” to that characteristic of metallike conductor. In this respect the nanocrystalline diamond electrodes
grown in the electrical arc plasma are similar to those grown in microwave plasma. 相似文献
7.
Yeong-Tarng Shieh Tzu-Yu Yu Tzong-Liu Wang Chien-Hsin Yang Wei-Tung Liao 《Colloid and polymer science》2012,290(1):1-9
In this study, we modified carbon nanotubes (CNTs) by grafting with poly(ethylene glycol) (PEG) using the “grafting to” method.
The PEG-grafted CNT (CNT-g-PEG) was cast on indium tin oxide (ITO) electrode to investigate the electrocatalytic activity
of CNT to the redox reactions of the Fe(CN)63−/4−as a probe using cyclic voltammetry and electrochemical impedance spectroscopy. The electrocatalytic activity of CNT was correlated
with CNT dispersion in the cast film on ITO as a function of pH of aqueous solution from which the film was cast. The CNT
dispersions in aqueous solutions of different pH and in the cast films were examined by visual observation and zeta potential,
scanning electron microscopy and transmission electron microscopy, respectively. At a pH in the range of 3–11 at which ITO
electrode was modified, two functionalized CNT (fCNT and CNT-g-PEG) were both found to electrocatalyze the redox reactions
of the Fe(CN)63−/4−probe and the PEG grafts in CNT-g-PEG could help CNT adhere to the electrode to obtain durable modified electrode. The more
uniform CNT dispersions in aqueous solutions and in the cast films appeared to have greater electrocatalytic acitivity. 相似文献
8.
Mohamed A. Ghanem Frank Marken Barry A. Coles Richard G. Compton 《Journal of Solid State Electrochemistry》2005,9(12):809-815
High intensity microwave radiation effects are demonstrated for electron transfer processes at 25 or 50-μm diameter platinum
electrodes immersed in micellar sodium dodecylsulfate (SDS) solutions. First, a solution containing 2 mM Fe(CN)63− and 2 mM Fe(CN)64− in aqueous 0.1 M NaCl with and without SDS is employed to calibrate the electrode temperature and mass transport conditions.
Addition of 0.1 M SDS has only a small effect on the microwave enhanced voltammetry for the Fe(CN)63-/4− system. Next, two highly water-insoluble redox systems are studied. A solution of 1 mM tert-butylferrocene in aqueous 0.1 M NaCl containing 0.1 M SDS is shown to give no current response in the absence of microwaves.
In the presence of focused microwaves at a platinum disc electrode, a strong current for the one electron oxidation of tert-butylferrocene is detected presumably due to localized disruption of the micellar solution. Concentrations of tert-butylferrocene down to the micromolar level are detected. α-Tocopherol, a lipophilic vitamin and antioxidant, is soluble
in aqueous 0.1 M SDS/0.1 M NaCl. In the presence of microwave radiation, a strong and concentration dependent anodic current
response consistent with the two-electron oxidation of α-tocopherol is observed. A heptode array of seven individual 50 μm
diameter platinum microelectrodes placed in ca. 720 μm distance of each other is shown to allow microwave enhanced currents
to be increased sevenfold with each electrode exhibiting the same microwave effect. 相似文献
9.
Electrochemical behavior of unitary or binary self-assembled monolayers with thiol-derivatized cobaltous porphyrin 总被引:1,自引:0,他引:1
A new thiol-derivatized metalloporphyrin, 5-{3-methoxyl-4-(4-mercaptobutoxy)}phenyl-10,15,20-triphenylporphyrincobalt (MBPPCo),
has been synthesized. The electrochemical behavior of unitary or binary self-assembled monolayers (SAMs) of MBPPCo and thiols
with carboxylic terminal groups was investigated using Fe(CN)6
3−/4− and ascorbic acid (AA) as probe species. The binary modified electrode showed a small increase in peak current but a large
decrease in overpotential. However, in anionic electroactive species [Fe(CN)6
3−/4− or AA], either positively charged MBPPCo or negatively charged thiol SAMs solely, slow electron transfer kinetics was obtained
and the possible reasons for the discrepancy are discussed. 相似文献
10.
Zheng Fang Shaofen Wang Zhenghua Zhang 《Journal of Thermal Analysis and Calorimetry》2011,106(3):937-943
An experiment was done on electrochemical–calorimetry to identify the Peltier heats of the ferro-ferricyanide reversible electrode
reaction over the concentration range of 0.075–0.3 mol dm−3 at 298.15 K. A new approach has been developed to obtain the standard potential of this electrode, which was identified as
(+0.3580 ± 0.0030) volt at 298.15 K and compared with previously reported values. An equation derived from the approach is
also applied to several standard couples, such as Fe(CN)6−3/Fe(CN)6−4, H+/H2, Cu2+/Cu, Cl−/Hg2Cl2,Hg, Fe3+/Fe2+, and Cl−/Cl2 to determine their respective reaction heats with satisfying results. 相似文献
11.
Chaopeng Fu Haihui Zhou Huimin Wu Jinhua Chen Yafei Kuang 《Colloid and polymer science》2008,286(13):1499-1504
The nonaqueous ionic liquid (IL) microemulsions composed of 1-butyl-3-methylimidazolium tetrafluoroborate, Triton X-100, and
toluene were prepared and the electrochemical properties of the nonaqueous IL microemulsions were investigated in this paper.
It is shown that characteristics of the nonaqueous IL microemulsions such as electrical conductivity, electrochemical window,
and solubility are good, which indicate that the nonaqueous IL microemulsions can be used as electrolyte for electrochemical
research. The electrochemical properties of the nonaqueous IL microemulsions were researched by cyclic voltammetry (CV) and
electrochemical impedance spectroscopy methods using potassium ferricyanide as electroactive probe. It was found that the
reversibility was better and the peak current densities of CV were higher for the [Fe(CN)6]3−/[Fe(CN)6]4− electrode reaction in the nonaqueous IL microemulsions than those in IL. However, the electrochemical behavior of the probe
in the nonaqueous IL microemulsions with different microenvironments (oil-in-IL, IL-in-oil, and bicontinuous) was different.
The electrochemical property of the probe in the oil-in-IL microemulsion was the best, which was studied in detail. 相似文献
12.
The sorption of anions H2PO4
−, HPO4
2−, PO4
3−, [Fe(CN)6]3−, and [Fe(CN)6]4− from aqueous solutions on the surface of FeIII and ZrIV oxyhydroxide hydrogels freshly precipitated at pH 4–13 was studied. The region of sorbate concentrations was from 0.00025
to 0.06 mol L−1. The plots of the anion uptakes vs. their equilibrium concentrations are represented by isotherms of the first type, which are well described by the Langmuir
equation if the quantity of the amount adsorbed is expressed as mol-site g−1. The maximum uptakes and constants of the Langmuir equation were calculated. The phosphate anions occupy the same number
of sorption sites on the sorbents precipitated at different pH. The average specific content of sorption sites for the ferro-
and zirconogels in the metastability period is independent of the pH of their precipitation, being 3.1·10−3 and 3.2·10−3 mol-site g−1, respectively. The [Fe(CN)6]3− and [Fe(CN)6]4− anions are sorbed only on the positively charged sites of the hydrogels and occupy not more than 2·10 mol-site g−1 in the studied interval of pH of precipitation.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1736—1741, August, 2005. 相似文献
13.
Muhammed Mizher Radhi Firas K. Mohamad Alosfur Noor J. Ridha 《Russian Journal of Electrochemistry》2018,54(1):27-32
In this study, a grafted polymer (GP) with ZnO nanoparticles (GP/ZnO NPs) was attached on the surface of glassy carbon electrode (GCE), in order to produce a new modified electrode (GP/ZnO NPs-GCE). The gamma irradiation method was used to grafted polystyrene (polymer) with acrylonitrile (monomer), while slow evaporation process was used to prepare the new modified electrode. The cyclic voltammetry (CV) of K4[Fe(CN)6] was used to study the electrochemical properties GP/ZnO NPs-GCE. The peak separation (ΔEpa-c) was 500 mV between the redox peaks of Fe(II)/Fe(III) in an aqueous solution of 1 M KCl and the current ratio of redox current peaks (Ipa/Ipc) was ≈ 1 for the modified electrode. This indicated that the modified electrode has s good reversibility and conductivity, wherefore; it was applied in the voltammetric filed. It was found that the modified electrode GP/ZnO NPs-GCE have a reasonable solubility and stability at various pH medium. Additionally, the sensitivity of the electrochemical analysis by cyclic voltammetric (CV) method is extensively subjected to the pH medium and the scan rate (SR). A couple of redox current peaks of K4[Fe(CN)6] in KCl solution was observed with a reversible process: Fe3+/Fe2+. Finally a good diffusion coefficient of electroactive species (D) for the new modified electrode was found in this study by chronoamperometry method using Cottrell equation. 相似文献
14.
Abstract
The derivatization of a glassy carbon electrode surface was achieved with and without electrochemical reduction of various diazonium salts in acetonitrile solutions. The surfaces were characterized, before and after their attachment, by cyclic voltammetry and electrochemical impedance spectroscopy to evidence the formation of a coating on the carbon surface. The results were indicative of the presence of substituted phenyl groups on the investigated surface. Also, the effects of diazonium thin films at the surface of a glassy carbon electrode, modification time, and salt concentration on their electrochemical responses in the presence of the Fe(CN)63−/4− probe were investigated. Electrochemical impedance measurements indicated that the kinetics of electron transfer is slowed down when the time and the concentration used to modify the glassy carbon electrode are increased. We therefore modified a glassy carbon surface via its derivatization with and without electrochemical reduction of various diazonium salts in acetonitrile solution. 相似文献15.
Baozhen Wang 《Talanta》2007,72(2):415-418
Multilayer thin films composed of poly(allylamine hydrochloride) (PAH) and carboxymethyl cellulose (CMC) have been prepared on the surface of a gold (Au) disk electrode by a layer-by-layer deposition of PAH and CMC and ferricyanide ions ([Fe(CN)6]3−) were confined in the film. [Fe(CN)6]3− ions can be successfully confined in the films from weakly acidic or neutral [Fe(CN)6]3− solutions, while, in basic solution, [Fe(CN)6]3− ion was not confined. The [Fe(CN)6]3− ion-confined Au electrode showed clear redox peaks in the cyclic voltammogram around 0.35 V versus Ag/AgCl. The amounts of [Fe(CN)6]3− ions confined in the films depended on the thickness of the films or the number of layers in the LbL films. The [Fe(CN)6]3− ion-confined Au electrode was used for electrocatalytic determination of ascorbic acid in the concentration range of 1-50 mM. 相似文献
16.
Amitava Dutta Mahammad Ali Sumana Gangopadhyay Pradyot Banerjee 《Journal of Chemical Sciences》1994,106(4):881-886
The electron transfer reactions of Mo(CN)8
4, W(CN)8
4− and Fe(CN)6
4− with the manganese (III) complex oftrans-cyclohexane-1,2-diamine-N,N,N′,N′-tetraacetic acid have been studied by stopped-flow spectrophotometry in the pH range 2.0–6.5.
Analysis of kinetic data conforms to an outer-sphere process in each case. The validity of Marcus’ crossreaction relation
to these reactions is fairly satisfactory. 相似文献
17.
Abolanle S. Adekunle Kenneth I. Ozoemena 《Journal of Solid State Electrochemistry》2008,12(10):1325-1336
Electrochemistry of edge-plane pyrolytic graphite electrodes (EPPGEs) modified with Aldrich single-walled carbon nanotubes
(SWCNTs) electro-decorated with metal (Ni, Fe and Co) and their oxides have been studied. The morphology and identity of the
metallic dispersions were examined by scanning electron microscopy and energy-dispersive spectroscopy. We show that SWCNTs
serve as efficient conducting carbon material for electronic communication between metal films and the underlying carbon electrode.
By using cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques, it is proved that both EPPGE-SWCNT-Ni
and EPPGE-SWCNT-Fe exhibit comparable electrochemical response in buffered aqueous solution (pH 7.0) and towards electro-oxidation
of hydrazine in Na2SO4 solution. The impedance spectra of these SWCNT-metal hybrids were complicated and follow electrical equivalent circuit model
typical of adsorption-controlled charge transfer kinetics. Hydrazine impedance spectra exhibited inductive loop, characteristic
of Faradaic current being governed by the occupation of an intermediate state. On the other hand, the EIS data obtained in
a simple redox probe, [Fe(CN)6]3−/[Fe(CN)6]4−, showed that EPPGE-SWCNT and EPPGE-SWCNT-Ni followed electrical equivalent circuit models typical of partial charge transfer
or adsorption-controlled kinetics with some resemblance to the behaviour of electrolyte–insulator–semiconductor sensors. 相似文献
18.
Noboru Oyama Takeo Ohsaka Takeyoshi Okajima Tomoaki Hirokawa Tsuyoshi Maruyama Yukio Ohnuki 《Journal of Electroanalytical Chemistry》1985,187(1):79-96
Liquid crystalline/polymer composite membrane-coated electrodes were prepared by casting a 1,2-dichloroethane solution of N-(4-ethoxybenzylidene)-4′-n-butylaniline (EBBA) and polycarbonate (PC) on an electrode surface. The temperature-dependence of the permeability of the EBBA/PC composite membrane on electrodes to Fe(CN)3?6 ion as a solution-phase redox ion was investigated by means of hydrodynamic voltammetry at a rotating disk electrode. The permeability changed with temperature over the range of the crystalline-nematic-phase transition temperature of EBBA. It is demonstrated that the observed temperature-dependence of the permeability reflects the thermotropic properties of EBBA in the EBBA/PC composite membrane. Furthermore, the dependence of the limiting current of the steady-state current-potential curves for the reduction of Fe(CN)—6 at the EBBA/PC composite membrane-coated electrode upon the membrane thickness, the blend ratio of EBBA and PC and the concentration of Fe(CN)3?6 in a bulk solution was examined in order to understand the transport process of Fe(CN)?36 through the EBBA/PC composite membrane from the membrane/solution interface to the electrode/membrane interface. The transport process of Fe(CN)3?6 within the membrane was found to obey Fick's Law. 相似文献
19.
M. H. Pournaghi-Azar H. Dastangoo R. Fadakar bajeh baj 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(1):75-81
In the present work the uranyl hexacyanoferrate (K2UO2[Fe(CN)6]) is deposited on the palladized aluminum (Pd-Al) electrode from a
\textUO22 + + \textFe( \textCN )6 - 3 {\text{UO}}_{2}^{2 + } + {\text{Fe}}\left( {\text{CN}} \right)_{6}^{ - 3} solution. Then the anodic stripping chronopotentiometry (ASCP) was used to strip the K2UO2[Fe(CN)6] from the Pd-Al surface. The operational conditions including: pH, K3Fe(CN)6 concentration, deposition potential, deposition time and stripping current were optimized. The ASCP calibration graph was
linear in concentration range 10–460 μM. of
\textUO22 + {\text{UO}}_{2}^{2 + } and the detection limit was 8.5 μM. The interference of some concomitant ions during the deposition process of K2UO2[Fe(CN)6] was studied. The proposed method was successfully applied for analysis of some uranium mineral ores. 相似文献
20.
Yu. V. Pleskov M. D. Krotova V. P. Varnin I. G. Teremetskaya 《Russian Journal of Electrochemistry》2010,46(3):325-330
The effect of nondiamond (sp
2-) carbon admixture on the surface of polycrystalline boron-doped CVD-diamond electrodes on their electrochemical behavior
was studied by comparing the films grown under similar conditions, yet of different thickness. It is shown that with the decreasing
of the film thickness (hence, with the increasing of the nondiamond carbon content therein) its surface acquired electrochemical
activity: the transfer coefficients of reactions in the [Fe(CN)6]3−/4− redox system increased, the oxygen anodic evolution overvoltage decreased, the differential capacitance increased; on the
whole, the diamond electrode demonstrated increasingly better pronounced metal-like behavior. 相似文献