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1.
Nafion- and clay-coated electrodes are prepared by casting a known amount of Nafion and clay solutions on the glassy carbon
electrode (GC) surface. Subsequently platinum (Pt) particles are deposited on the GC electrodes and on the Nafion- and clay-coated
GC electrodes. The formation of Pt particles on the modified electrode surface is analysed by scanning electron microscope,
while cyclic voltammetry provides information on the anodisation of Pt particles deposited on the GC electrodes at >0.5 V(SCE)
leading to the formation of platinum oxide (PtO). The involvement of PtO on the catalysed dioxygen reduction to hydrogen peroxide
is reported. Macrocyclic cobalt(III) complex is also used as the electrocatalyst. The effect of pH on the reduction of PtO
and dioxygen in deaerated and oxygenated solutions is studied to understand the dioxygen reduction processes.
Received: 24 January 1997 / Accepted: 14 April 1997 相似文献
2.
Hong Shen James E. Mark Carl J. Seliskar Harry B. Mark Jr. William R. Heineman 《Journal of Solid State Electrochemistry》1997,1(3):241-247
One problem associated with using bare solid metal electrodes, such as gold and platinum, in stripping analysis to determine
heavy metal ions such as lead and copper ions in dilute solutions is that underpotential deposition (UPD) gives multiple stripping
peaks in the analysis of mixtures. These peaks are often overlapped and cannot be conveniently used for analytical purposes.
Bifunctional alkylthiols, such as 3-mercaptopropionic acid, with an ionizable group on the other terminal end of the thiol
can form self-assembled monolayers (SAMs) on the surface of the gold electrode. It is shown that such an SAM-modified gold
electrode minimizes the UPD effects for the stripping analysis of lead and copper. The anodic peak potential shifts and the
peak shape changes, indicating that the SAM changes the deposition and stripping steps of these heavy metal ions. Thus, the
sensitivity levels for both single species and mixtures can be significantly improved for the conventional solid electrodes.
The mechanism of the deposition reaction at the SAM-modified gold electrodes is discussed.
Received: 29 May 1997 / Accepted: 24 June 1997 相似文献
3.
C. Faller G. Henze N. Stojko S. Saraeva K. Brainina 《Fresenius' Journal of Analytical Chemistry》1997,358(6):670-676
The paper describes the determination of tin by ASV using modified thick film electrodes. Three different types of electrodes
were developed: One modified with a mixture of Nafion and mercury(II)acetate, one modified with diethyldithiocarbamate (DDC)
or pyrrolidinedithiocarbamate (PDC) and mercury(II)acetate, and one modified with calomel. The analyte was accumulated on
the electrode surface after special electrochemical pretreatment of the modified electrode. After recording the voltammogram
the electrodes were electrochemically regenerated. By virtue of their lifetime and their measurement reproducibility, we preferred
the DDC and PDC modified electrodes. They can be used for months without changing their chemical characteristics. The linear
range for tin determination with these electrodes is between 1 and 100 μg/L; the detection limit was calculated as 0.9 μg/L.
The electrodes were applied to the direct determination of tin in different canned fruit juices without special sample pretreatment.
Received: 20 December 1996 / Revised: 11 March 1997 / Accepted: 13 March 1997 相似文献
4.
C. Faller G. Henze N. Stojko S. Saraeva K. Brainina 《Analytical and bioanalytical chemistry》1997,358(6):670-676
The paper describes the determination of tin by ASV using modified thick film electrodes. Three different types of electrodes
were developed: One modified with a mixture of Nafion and mercury(II)acetate, one modified with diethyldithiocarbamate (DDC)
or pyrrolidinedithiocarbamate (PDC) and mercury(II)acetate, and one modified with calomel. The analyte was accumulated on
the electrode surface after special electrochemical pretreatment of the modified electrode. After recording the voltammogram
the electrodes were electrochemically regenerated. By virtue of their lifetime and their measurement reproducibility, we preferred
the DDC and PDC modified electrodes. They can be used for months without changing their chemical characteristics. The linear
range for tin determination with these electrodes is between 1 and 100 μg/L; the detection limit was calculated as 0.9 μg/L.
The electrodes were applied to the direct determination of tin in different canned fruit juices without special sample pretreatment.
Received: 20 December 1996 / Revised: 11 March 1997 / Accepted: 13 March 1997 相似文献
5.
Mustafa Özden Ergun Ekinci A. Ersin Karagözler 《Journal of Solid State Electrochemistry》1998,2(6):427-431
A polyindoline permselective polymer film was readily synthesized by an electrochemical polymerization of indoline in an
aqueous solution of KCl at a potential of 0.4 V vs Ag/AgCl. The amperometric responses of the polyindoline film-coated platinum
electrodes to electroactive (ascorbic acid, oxalic acid and hydrogen peroxide) and non-electroactive (lactose, sucrose and
urea) substances were measured at a potential of 0.7 V. Effects of various variables such as film thickness, concentrations
of monomer and electrolyte, and pH on the permselective behavior of the polymeric membrane were systematically investigated
and the optimal values were determined. It was found that permselective polyindoline-coated electrodes prepared in this one-step
procedure permitted hydrogen peroxide oxidation while it prevented interference due to oxidizable species such as ascorbic
acid and oxalic acid. As a result, it is believed that this polymeric membrane, owing to its permselective character, can
be used as the protective material in the construction of hydrogen peroxide-based biosensors.
Received: 10 November 1997 / Accepted: 27 January 1998 相似文献
6.
M. Soledad Ureta-Zañartu Claudia Yáñez Gloria Reyes José Ramón Gancedo José F. Marco 《Journal of Solid State Electrochemistry》1998,2(3):191-197
The activity of Pt-Ir deposits on titanium for the reduction of the nitrate ion in 0.5 M perchloric acid was studied. The
electrodes were characterized by SEM-EDAX, XPS and cyclic voltammetry. The activity of the electrodes for the nitrate reduction
depended on the Pt-Ir ratio. Repetitive cyclic voltammograms produced an enrichment of the electrode surface with Ir and a
decrease of the catalytic activity. A synergistic effect in the electrodes with low iridium content is discussed.
Received: 2 June 1997 / Accepted: 28 August 1997 相似文献
7.
Vladislav V. Kharton Evgeny N. Naumovich Alim A. Vecher 《Journal of Solid State Electrochemistry》1999,3(2):61-81
Developments of solid electrolytes and mixed conductors based on stabilized zirconia in the former Soviet Union are reviewed.
Primary attention is given to experimental data on high-conducting electrolytes, mixed conductors obtained by doping zirconia
with transition metal oxides, oxygen exchange and oxygen permeation processes, as well as properties of metal electrodes in
contact with the stabilized zirconia.
Received: 26 March 1998 / Accepted: 4 June 1998 相似文献
8.
Substitution of classical lead anodes containing 6–8% of antimony, 4–6% of tin or 0.75–1.00% of silver in the zinc electrowinning
and hard chromium plating bath with platinized and activated titanium anodes is discussed in this paper. Depending on the
type of electrochemical processes, the main effects of this substitution are as follows: smaller electrical energy consumption,
better current efficiency, increased cell capacity, smaller electrode gap, higher purity of the deposit and savings in manpower
and chemicals. Ti/Pt, Ti/Pt-IrO2, Ti/RuO2, Ti/Pt-IrO2-MnO2, Ti/Pt-IrO2-PbO2, Ti/Pt-IrO2-RuO2, Ti/MnO2, Ti/RuO2-MnO2 and Ti/PbO2 coated titanium anodes have been tested in synthetic as well as in industrial electrolytes. At working current densities
some activated titanium anodes showed lower overpotential than the lead anode. These electrodes have continued to perform
in this way during a one-year test in synthetic and industrial electrolytes so far. No signs of corrosion of the electrodes
have been noticed during the test.
Received: 31 January 1997 / Accepted: 28 May 1997 相似文献
9.
Suárez-Herrera MF Costa-Figueiredo M Feliu JM 《Langmuir : the ACS journal of surfaces and colloids》2012,28(11):5286-5294
The first part of this report studies the electrochemical properties of single-crystal platinum electrodes in acetonitrile electrolytes by means of cyclic voltammetry. Potential difference infrared spectroscopy in conjunction with linear voltammetry was used to obtain a molecular-level picture of this interface. The second part of this report studies the hydrogen evolution and the hydrogen oxidation reactions on the three low-index faces of Pt electrodes in acetonitrile electrolytes. The data (CVs and IR spectra) strongly suggest that acetonitrile and CN(-) molecules are adsorbed on single-crystal platinum electrodes in the range of -1.5 to 0.3 V versus Ag/AgCl. Those species block part of the adsorption sites for hydrogen adatoms, and they decompose on the surface in the presence of water. The nature of the cation and the presence of water strongly affect the onset of acetonitrile electrolysis and the kinetics and stability of the adsorbed species on the electrode. Finally, the hydrogen evolution and the hydrogen oxidation reactions on platinum single-crystal surfaces in acetonitrile electrolytes are strongly affected by the surface-energy state of Pt electrodes. 相似文献
10.
A flow injection on-line sorption preconcentration method for the electrothermal AAS determination of platinum has been developed.
The pyrrolidine dithiocarbamate complexes of either Pt4+ or Pt2+, formed in 0.7 mol L–1 HNO3, are on-line adsorbed on the inner walls of a PTFE knotted reactor and subsequently eluted with methanol. An enhancement
factor of 112 and a detection limit (3 σ) of 10 ng L–1 along with a sampling frequency of 21 h–1 are achieved with a 90 s preconcentration time at a sample flow rate of 8.8 mL min–1. The relative standard deviation is 2.5% for 0.4 μg L–1 Pt. The method has been applied to the determination of platinum in blood samples.
Received: 6 October 1997 / Revised: 26 November 1997 / Accepted: 3 December 1997 相似文献
11.
The effects of temperature on lithium intercalation into non-graphitized carbonized cloth from various electrolytes have
been studied. The open-circuit potential (o.c.p.) of the intercalates shifts in the negative direction as the temperature
is raised. The average temperature coefficient of the o.c.p. is equal to −0.04 mV·K−1 in the range from −35 to +45 °C. Intercalation-deintercalation kinetics was studied by the galvanostatic technique. It was
shown that this process is quasi-ohmic at room and higher temperatures and has activation-ohmic control at lower temperatures.
The effective activation energy of intercalation-deintercalation is about 20kJ·mol−1. Intercalates are corroded in all electrolytes, the corrosion rate being drastically increased as the temperature is raised.
The apparent activation energy of corrosion is 120–150 kJ·mol−1. The corrosion rate is suggested to be controlled by cathodic reduction of electrolyte components.
Received: 11 April 1997 / Accepted: 8 September 1997 相似文献
12.
Vyacheslav Vasilevich Slepushkin Boris Mikhailovich Stifatov Sergei Borisovich Stifatov Irina Alexandrovna Tikhonova 《Journal of Solid State Electrochemistry》1999,3(4):234-238
Local electrochemical analysis with a pressed-on electrochemical cell is suggested for the estimation of the quality of coatings
protecting the surface of materials, for the detection of different defects and for the control of the thickness and composition
of coatings. The suggested local electrochemical analysis allows the determination of the throwing power of the electrolytes
used in electrodepositions.
Received: 8 December 1997 / Accepted: 21 August 1998 相似文献
13.
V. V. Kuznetsov B. I. Podlovchenko K. V. Kavyrshina Yu. M. Maksimov 《Russian Journal of Electrochemistry》2010,46(12):1353-1359
The electrocatalytic Pt-Mo system was obtained by formation of platinum particles on the Mo surface under its contact with
PtC62− (PtCl42−) under the open circuit conditions. Cyclic voltammograms of the obtained Pt(Mo) electrodes feature well pronounced peaks
of hydrogen adsorption and desorption on Pt particles. Nonuniform platinum distribution across the electrode surface was found.
Pt(Mo) electrodes showed a higher specific activity in the reaction of methanol oxidation in the potential range of 0.35–0.45
V (RHE) as compared to Pt/Pt. 相似文献
14.
Nickel foam and five nickel foam-based composite electrodes were prepared for being used as anode materials for the electrooxidation
of methanol in KOH solution containing 0.1 and 1.0 M of methanol. The layered electrodes composed of nickel foam, platinum
nanoparticles, polyaniline (PANI) and/or porous carbon (C) prepared in various assemblies. As shown by SEM analysis, depending
on the preparation conditions, the electrodes of different morphologies were obtained. Using the cyclic voltammetry method,
the oxidation of methanol on nickel foam electrode was observed in the potential range 0.4 V ↔ 0.7 V, where the Ni(OH)2/NiOOH transformation occurred. The presence of Pt particles in electrode gave rise to the increase in electrocatalytic activity
in this potential range. For electrodes containing dispersed platinum catalyst (Ni/Pt, Ni/PANI/Pt and Ni/C/Pt), the oxidation
of methanol was noted also in the potential range −0.5 V ↔ 0.1 V. The electrocatalytic activities of the examined electrodes
toward methanol oxidation at low potentials were in order Ni/Pt > Ni/C/Pt > Ni/PANI/Pt, whereas at high potentials in order
Ni/PANI/Pt > Ni/Pt> Ni/C/Pt > Ni. Among the examined electrodes, the most resistant to cyclic poisoning appeared to be the
Ni/C/Pt electrode.
Presented at the 4Th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
15.
Helmut Bönnemann Guram Khelashvili Silke Behrens Andreas Hinsch Krzysztof Skupien Eckhard Dinjus 《Journal of Cluster Science》2007,18(1):141-155
The publication covers materials and cluster science aspects of the platinum counter electrode (CE) in the “monolithic type”
dye sensitized solar cell systems (DSSC). Nanocluster based catalytic platinum layers are utilized for the iodide/triiodide
reduction in different electrolytes. Various preparative methods have been applied for the preparation of platinum nanoparticles
for the CE. The structure, properties, and performance of the different nanoparticles obtained by thermal decomposition of
H2PtCl6, triorganohydroborate reduction of a platinum salt, reductive stabilization of Pt(acac)2 by trialkylaluminium, the “polyol method”, and the reduction of the H2PtCl6 by hydrogen are compared. The oxidation states of the platinum surface- and core-atoms were analyzed by X-Ray Photoelectron
Spectroscopy (XPS) and X-ray Absorption Near Edge Structure (XANES) respectively. Size and the crystalline structure of the
particles were investigated by Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD). The charge transfer resistance
of the different catalytic platinum layers resulted from the above mentioned preparative methods, was compared by electrochemical
impedance spectroscopy (EIS).
Dedicated to Prof. Günter Schmid on the occasion of 70th anniversary 相似文献
16.
J. D. B. Smith D. C. Phillips D. H. Davies 《Journal of polymer science. Part A, Polymer chemistry》1977,15(7):1555-1562
The electrochemically initiated polymerization of styrene in methylene chloride solvent with the use of platinum electrodes and tetraalkyl and -aryl group VA halides (i.e., quaternary ammonium, phosphonium, and arsonium compounds) as electrolyte has been investigated. The order of reactivity of the electrolytes with respect to polymerization rate and initiation efficiency was found to be: arsonium > phosphonium > ammonium. Mechanisms involving the electroreduction of the group VA quaternary halides to species capable of electroinitiating polymerization are postulated. The observed losses in solution conductivities during polymerization with the quaternary phosphonium and arsonium electrolytes indicate possible interaction between the initiating radical-ionic species and the supporting electrolyte. In an attempt to further elucidate the mechanism of initiation in these systems, a separate series of experiments, employing the nonpolymerizing monomer, 1,1-diphenylethylene, has been carried out. 相似文献
17.
Janina Janisch Adrian Ruff Bernd Speiser Christian Wolff Jonas Zigelli Steffi Benthin Verena Feldmann Hermann A. Mayer 《Journal of Solid State Electrochemistry》2011,15(10):2083-2094
Cyclic voltammetry data recorded at disk macro- (millimeter dimension) and microelectrodes (10 and 100 μm) at various scan
rates are used to simultaneously determine the diffusion coefficient D of ferrocene (fc) and the electroactive surfaces A and/or radii r of the electrodes. A case study with three electrodes of different sizes in CH3CN- and propylene carbonate (PC)-based electrolytes shows the possibly large effect of incorrect D values. Diffusion coefficients of fc are determined for PC, CH3CN, CH2Cl2, DMF, and DMSO electrolytes and (except for PC) compared to those from pulse-gradient spin-echo nuclear magnetic resonance
experiments in the presence of supporting electrolyte in the respective deuterated solvents. The dependence of D
fc on solvent viscosity is shown to follow the Stokes–Einstein relation. 相似文献
18.
A new method is described for the determination of ammonium in aqueous solutions with electrodes modified by Prussian blue
(PB). The specific voltammetric response of PB-modified electrodes to ammonium ions is used for their analytical determination.
In the presence of ammonium ions, a concentration-dependent inhibition of the low-spin iron(II/III) system of PB occurs. Only
thallium and rubidium ions cause similar inhibition. A useful electrochemical determination method is thus available for detecting
ammonium ions in the presence of frequently interfering potassium and sodium ions. Paraffin-impregnated graphite electrodes
modified with a mechanically transferred PB layer and bulk-modified PB-composite electrodes are studied. The method is applicable
within a concentration range which extends from 4 × 10−5 mol/l to 10−2 mol/l NH4
+. The composite electrode is used in an electrochemical flow-through system in conjunction with the Kjeldahl method.
Received: 21 April 1997 / Accepted: 28 May 1997 相似文献
19.
D. I. Bronin B. L. Kuzin I. Yu. Yaroslavtsev N. M. Bogdanovich 《Journal of Solid State Electrochemistry》2006,10(8):651-658
The electrochemical cells with electrodes based on La0.8Sr0.2MnO3 (LSM) and supporting solid electrolytes La0.88Sr0.12Ga0.82Mg0.18O2.85 (LSGM) and Ce0.80Sm0.20O1.90 (SDC) were studied comparatively. Characteristics of LSM electrodes and composite electrodes comprising a mixture of LSM
and electrolytes of different origins [LSGM, SDC, and Zr0.82Sc0.18O1.91 (SSZ) in the mass ratio of 1:1] were analyzed. It was shown that: 1) the electrode polarization conductivity and the ohmic
resistance of the cells with the LSM–LSGM composite electrodes on the LSGM and SDC electrolytes had very similar values, while
they were largely different from all the other electrodes, 2) the electrochemical activity of the electrodes on the SDC electrolyte
was much higher than on the LSGM electrolyte, and 3) the ohmic resistance of the cells with the SDC electrolyte corresponded
to the electrolyte resistance, whereas, the ohmic resistance of the cells with the LSGM electrolyte was much larger than the
electrolyte resistance. The obtained results are due to the interaction between the LSM and LSM-containing electrodes with
the LSGM electrolyte during sintering, leading to the formation of a product with a very low conductivity. 相似文献
20.
The transport and kinetics of potential electrolytes (such as weak organic acids) at stationary and rotating electrodes have
been examined in detail. A coherent mathematical analysis enabling the normalised current response to be evaluated has been
developed, and various rate limiting scenarios have been identified and examined.
Received: 13 March 1998 / Accepted: 31 July 1998 相似文献