The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Boris I. Podlovchenko - One of the best experts on this subject based on the ideXlab platform.
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Special Features of Methanol Interaction with Adsorbed Oxygen at Platinized Platinum Electrode: Transients of the Open-Circuit Potential
Russian Journal of Electrochemistry, 2007Co-Authors: R. A. Manzhos, Boris I. Podlovchenko, Yu M MaksimovAbstract:Open-Circuit Potential transients are measured under the conditions of methanol interaction with the pre-adsorbed oxygen at platinized platinum electrode. The time necessary for complete removal of the adsorbed oxygen monolayer appeared being shorter by a factor of ∼1.5 as compared with smooth polycrystalline platinum. The dependence of platinum surface coverage with adsorbed oxygen on the Potential during its decay is found. It was shown that the reaction of methanol with the adsorbed oxygen is most slow at a high coverage (1–0.8). It is suggested that at these coverages, like the case of polycrystalline platinum, the adsorbed oxygen directly interacts with the methanol molecules from the solution. At moderate coverages (0.8–0.2), the reaction of the adsorbed oxygen with methanol at the platinized platinum is better described by the “conjugated reactions” mechanism. The specific rates of the methanol dissociative adsorption at the platinized platinum turned out to be close to those observed earlier for the polycrystalline platinum.
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Kinetics and Mechanism of Interaction between Methanol and Adsorbed Oxygen on a Smooth Polycrystalline Platinum Electrode: Transients of the Open-Circuit Potential
Russian Journal of Electrochemistry, 2006Co-Authors: Boris I. Podlovchenko, R. A. Manzhos, Yu M MaksimovAbstract:The method of transients of the Open-Circuit Potential, combined with cathodic potentiodynamic pulses, is used for studying the methanol interaction with preliminarily adsorbed oxygen (Oads) in 0.5 M H2SO4. It is established that, for the larger part of the time period required for a full reduction of a monolayer of Oads in solutions of methanol on polycrystalline platinum, the process occurs at large coverages of the surface by Oads (ϑO). In the region of medium coverages, transients of the Open-Circuit Potential are accurately described by the equation that corresponds to the mechanism of “conjugated reactions.” The mechanism of the methanol interaction with Oads happens to be close to that for formic acid, which is explained by a dissociative character of these HCO compounds. Kinetic parameters characterizing the methanol reaction with Oads in the region of large and medium coverages are determined and analyzed.
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Specific features of interaction between formic acid and oxygen adsorbed on smooth polycrystalline platinum: Transients of the Open-Circuit Potential
Russian Journal of Electrochemistry, 2006Co-Authors: R. A. Manzhos, Boris I. Podlovchenko, Yu M MaksimovAbstract:Transients of the Open-Circuit Potential, which are observed when formic acid is interacting wit adsorbed oxygen (Oads) preliminarily accumulated on polycrystalline “smooth” platinum (pcPt), are measure in an aqueous solution of sulfuric acid. It is shown that, as with platinized platinum (Pt/Pt), at large coverage by adsorbed oxygen (θO = 1−0.8), adsorbed oxygen interacts directly with molecules of formic acid from solution. In the region of medium coverages (θO = 0.8−0.2), on the other hand, a mechanism of “conjugated reactions” is realized. It is established that, in the case of pcPt, the direct interaction of Oads with molecules of HCOOH from solution proceeds slower by nearly three times and the interaction via the mechanism of “conjugated reactions,” faster by about three times, as compared with Pt/Pt.
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Transients of the Open-Circuit Potential Observed during the Interaction of Formic Acid with Preliminarily Adsorbed Oxygen on a Platinized Platinum Electrode
Russian Journal of Electrochemistry, 2005Co-Authors: R. A. Manzhos, Yu M Maksimov, Boris I. PodlovchenkoAbstract:Transients of the Open-Circuit Potential, which are observed during the interaction of formic acid with preliminarily adsorbed oxygen (Oads) on a Pt/Pt electrode in 0.5 M H2SO4, are measured. It is established, by means of the method of cathodic potentiodynamic pulses, that the slowest interaction of formic acid with Oads occurs in the region of large coverages of the electrode surface by oxygen (θO ∼1–0.8). A presumption is put forward that the process rate in this region is defined by a direct reaction of Oads with molecules of formic acid from the bulk solution. It is shown that the interaction of formic acid with Oads in the region of intermediate coverages (θO ∼ 0.8–0.2) proceeds via a mechanism of “conjugated reactions.” Transients of the Open-Circuit Potential for formic acid are compared to transients for carbon monoxide obtained in analogous conditions. The substantially shorter overall time of Potential decay in the case of CO (at the same concentrations) is caused by a faster reaction of CO with adsorbed oxygen in the region of large θO. The difference is explained by assuming that the HCOOH adsorption as opposed to CO bears a dissociative character.
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Experimental check-up of the relationship between transients of current and Open Circuit Potential for strong adsorption of neutral species and ions on a hydrogen electrode
Journal of Electroanalytical Chemistry, 2003Co-Authors: Boris I. Podlovchenko, T. D. Gladysheva, E. A. KolyadkoAbstract:Abstract Transients of current and Open Circuit Potential are measured during carbon monoxide adsorption on Pt/Pt, Rh/Pt, and Ir/Pt electrodes from sulfuric acid and hydrochloric acid solutions, as well as during the adsorption of iodine and iodide ions on Pd/Pt from sulfuric acid solutions. The integral values of transients are shown to agree with those expected theoretically. The possibility of estimating Open Circuit Potential transients based on the data on current transients is analyzed. A combination of transient measurements with other adsorption methods makes it possible to show that in a number of systems the electrode surface is recharged as a result of formation of adsorbed monolayers and to reveal differences in the nature of adlayers formed in solutions of I2 and I−.
F. Oberholtzer - One of the best experts on this subject based on the ideXlab platform.
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A Reaction‐Plane Model for the Open‐Circuit Potential of Copper in Aerated Copper Sulfate Solution
Journal of The Electrochemical Society, 1998Co-Authors: Dale P. Barkey, F. OberholtzerAbstract:A reaction-plane model is used to examine the behavior of copper in aerated acid sulfate solution at or near the Open-Circuit Potential. The model predicts that when dissolved oxygen is present, the metal will corrode at a mixed Potential determined by the Cu 2+ /Cu 1+ and Cu 1+ /Cu couples. The mixed Potential in an aerated solution is negative to the equilibrium Potential in a deaerated solution; it is controlled by the kinetics of the Cu 2+ /Cu 1+ couple and by diffusion of oxygen to a reaction plane where cuprous ion is consumed. The computed Potentials are compared with measured Open-Circuit Potentials of copper single crystals with orientations of (100), (110), and (111). Galvanic cells that could arise under this mechanism are explored with the model.
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a reaction plane model for the Open Circuit Potential of copper in aerated copper sulfate solution
Journal of The Electrochemical Society, 1998Co-Authors: Dale P. Barkey, F. OberholtzerAbstract:A reaction-plane model is used to examine the behavior of copper in aerated acid sulfate solution at or near the Open-Circuit Potential. The model predicts that when dissolved oxygen is present, the metal will corrode at a mixed Potential determined by the Cu 2+ /Cu 1+ and Cu 1+ /Cu couples. The mixed Potential in an aerated solution is negative to the equilibrium Potential in a deaerated solution; it is controlled by the kinetics of the Cu 2+ /Cu 1+ couple and by diffusion of oxygen to a reaction plane where cuprous ion is consumed. The computed Potentials are compared with measured Open-Circuit Potentials of copper single crystals with orientations of (100), (110), and (111). Galvanic cells that could arise under this mechanism are explored with the model.
Zdeněk Samec - One of the best experts on this subject based on the ideXlab platform.
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Open Circuit Potential transients associated with single emulsion droplet collisions at an interface between two immiscible electrolyte solutions
Electrochemistry Communications, 2018Co-Authors: Antonin Trojanek, Vladimir Marecek, Zdeněk SamecAbstract:Abstract Measurements of the Open Circuit Potential (OCP) transients at a sessile aqueous electrolyte drop in contact with a 1,2-dichloroethane (DCE) electrolyte solution were used to detect the collisions of the single DCE-in-water emulsion droplets carrying 0.35 M tetradodecylammonium chloride with the interface between two immiscible electrolyte solutions (ITIES). Analysis of the OCP transients yielded the droplet size distribution, which is comparable with distributions obtained from the current transient measurements at a constant applied Potential. These results are supported by the dynamic light scattering measurements and the microscope droplet image processing. Observed Potential or current spikes appear to be associated with the single collisions of the emulsion droplets with the ITIES followed by the fast droplet ionic charge injection into the electric double layer at the ITIES possibly involving the transfer of Cl − across the droplet/aqueous phase interface, and by the double layer relaxation.
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Open Circuit Potential transients associated with single emulsion droplet collisions at an interface between two immiscible electrolyte solutions
Elsevier, 2018Co-Authors: Antonin Trojanek, Vladimir Marecek, Zdeněk SamecAbstract:Measurements of the Open Circuit Potential (OCP) transients at a sessile aqueous electrolyte drop in contact with a 1,2-dichloroethane (DCE) electrolyte solution were used to detect the collisions of the single DCE-in-water emulsion droplets carrying 0.35M tetradodecylammonium chloride with the interface between two immiscible electrolyte solutions (ITIES). Analysis of the OCP transients yielded the droplet size distribution, which is comparable with distributions obtained from the current transient measurements at a constant applied Potential. These results are supported by the dynamic light scattering measurements and the microscope droplet image processing. Observed Potential or current spikes appear to be associated with the single collisions of the emulsion droplets with the ITIES followed by the fast droplet ionic charge injection into the electric double layer at the ITIES possibly involving the transfer of Cl− across the droplet/aqueous phase interface, and by the double layer relaxation. Keywords: ITIES, OCP transient, Current transient, Emulsion droplet, Single collision, Droplet size distributio
Michael Grätzel - One of the best experts on this subject based on the ideXlab platform.
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subnanometer ga2o3 tunnelling layer by atomic layer deposition to achieve 1 1 v Open Circuit Potential in dye sensitized solar cells
Nano Letters, 2012Co-Authors: Aravind Kumar Chandiran, Nicolas Tetreault, Robin Humphrybaker, Florian Kessler, Etienne Baranoff, Chenyi Yi, Mohammad Khaja Nazeeruddin, Michael GrätzelAbstract:Herein, we present the first use of a gallium oxide tunnelling layer to significantly reduce electron recombination in dye-sensitized solar cells (DSC). The subnanometer coating is achieved using atomic layer deposition (ALD) and leading to a new DSC record Open-Circuit Potential of 1.1 V with state-of-the-art organic D-π-A sensitizer and cobalt redox mediator. After ALD of only a few angstroms of Ga2O3, the electron back reaction is reduced by more than an order of magnitude, while charge collection efficiency and fill factor are increased by 30% and 15%, respectively. The photogenerated exciton separation processes of electron injection into the TiO2 conduction band and the hole injection into the electrolyte are characterized in detail.
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Influence of the Sensitizer Adsorption Mode on the Open-Circuit Potential of Dye-Sensitized Solar Cells
Nano letters, 2007Co-Authors: Filippo De Angelis, Simona Fantacci, Annabella Selloni, Michael Grätzel, Mohammed Khaja NazeeruddinAbstract:We report a combined experimental and theoretical study on the origin of the different Open Circuit Potentials observed in dye-sensitized solar cells using Ru(II)-polypyridyl homoleptic and heteroleptic sensitizers. We have measured the photovoltaic data of different sensitizers and used DFT calculations to analyze the electronic structure of dye-sensitized TiO2 nanoparticles. Heteroleptic sensitizers adsorb onto TiO2 via a single bipyridine, leading to a TiO2 conduction band downshift and overall reduction of the cell Open Circuit Potential.
Mohammed Khaja Nazeeruddin - One of the best experts on this subject based on the ideXlab platform.
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Influence of the Sensitizer Adsorption Mode on the Open-Circuit Potential of Dye-Sensitized Solar Cells
Nano letters, 2007Co-Authors: Filippo De Angelis, Simona Fantacci, Annabella Selloni, Michael Grätzel, Mohammed Khaja NazeeruddinAbstract:We report a combined experimental and theoretical study on the origin of the different Open Circuit Potentials observed in dye-sensitized solar cells using Ru(II)-polypyridyl homoleptic and heteroleptic sensitizers. We have measured the photovoltaic data of different sensitizers and used DFT calculations to analyze the electronic structure of dye-sensitized TiO2 nanoparticles. Heteroleptic sensitizers adsorb onto TiO2 via a single bipyridine, leading to a TiO2 conduction band downshift and overall reduction of the cell Open Circuit Potential.
