Search results for "Electrode"

A Comparative Study of Poly(Azure A) Film-Modified Disposable Electrodes for Electrocatalytic Oxidation of H₂O₂: Effect of Doping Anion.

2018

In the present paper, poly(azure A) (PAA) films were electrosynthetized in the presence of different doping anions on disposable screen-printed carbon electrodes (SPCEs). The anions used included inorganic monoatomic (chloride and fluoride), inorganic polyatomic (nitrate and sulfate) and organic polyatomic (dodecyl sulfate, DS) species. The coated electrodes thus obtained were characterized by electrochemical techniques and SEM. They showed improved electrocatalytic activities towards hydrogen peroxide oxidation compared to that of a bare SPCE. In particular, the insertion of DS anions inside PAA films provided a special sensitivity to the electrocatalysis of H2O2, which endowed these elect…

Porous Anodic Alumina as template for the cathodic electrodeposition of oxide and hydroxide nanostructures

2009

Clarification of the oxidation state of cobalt corroles inheterogeneous and homogeneous catalytic reduction of dioxygen

2008

Co(III) corroles were investigated as efficient catalysts for the reduction of dioxygen in the presence of perchloric acid in both heterogeneous and homogeneous systems. The investigated compounds are (5,10,15-tris(pentafluorophenyl)corrole)cobalt (TPFCor)Co, (10-pentafluorophenyl-5,15-dimesitylcorrole)cobalt (F 5PhMes 2Cor)Co, and (5,10,15-trismesitylcorrole)cobalt (Mes 3Cor)Co, all of which contain bulky substituents at the three meso positions of the corrole macrocycle. Cyclic voltammetry and rotating ring-disk electrode voltammetry were used to examine the catalytic activity of the compounds when adsorbed on the surface of a graphite electrode in the presence of 1.0 M perchloric acid, a…

Thermodynamics of Electrochemical Systems

2004

A discussion of the fundamentals of thermodynamic theory describing electrochemical systems is presented. The basic relationships are deduced as properties of the electrochemical potential. The theory introduces an observable electric potential that is defined at every position within the electrochemical system as the potential of a reversible electrode placed there. To provide a good test of the formalism, five systems have been studied including equilibrium and nonequilibrium. The formalism emphasizes the advantages of the electric current density in order to characterize one of the degrees of irreversibility and the electrical equilibrium. Finally, the electrostatic potential is discusse…

Review of gas diffusion cathodes for alkaline fuel cells

2009

Abstract This paper gives a technical background to alkaline fuel cells (AFCs), introducing the advantages and drawbacks of the technology. AFCs offer the potential for low cost, mass producible fuel cells, without the dependency on platinum based catalysts and (currently) expensive membrane electrolytes. The AFC uses relatively low cost electrolytes based on aqueous bases such as potassium hydroxide. The inherent CO 2 sensitivity of the electrolyte can be addressed by filtering out the CO 2 from the air intake using a simple scrubber and periodically replacing the liquid electrolyte. A review of the state-of-the-art in gas diffusion cathode development is given. The overall cell performanc…

Electrodeposited nickel–zinc alloy nanostructured electrodes for alkaline electrolyzer

2022

Abstract Over the last decade, as a consequence of the global decarbonization process, the interest towards green hydrogen production has drastically increased. In particular a substantial research effort has focused on the efficient and affordable production of carbon-free hydrogen production processes. In this context, the development of more efficient electrolyzers with low-cost electrode/electrocatalyst materials can play a key role. This work, investigates the fabrication of electrodes of nickel-zinc alloys with nanowires morphology cathode for alkaline electrolyzers. Electrodes are obtained by the simple method of template electrosynthesis that is also inexpensive and easily scalable.…

Inhibition Probing on a Cut-Edge Electrode Machined from a Primer-Coated 2024-T3 Alloy

2013

Conventional corrosion protection of 2024-T3 alloys (AA2024T3) in aeronautic structures combines conversion coating with chromate-inhibited primer protected by a top-coat. In some cases this protection can break down after mechanical damage to the paint systems inducing a risk of localized corrosion if the release of inhibitors trapped in the primer does not reach a critical level. There is a need for developing computational models combining the inhibitor release and transport within and from the coating system andthecorrosioninhibitionprocess,toassistinthedesignofnewmultifunctionalcoatingsystems.Theinfluenceonthecorrosioninhibition of various parameters such inhibitor release rate, defect…

EIS and Ac-electrogravimetry study of PB films in KCl, NaCl, and CsCl aqueous solutions

2003

Prussian Blue films have been studied by means of ac-electrogravimetry, electrochemical impedance spectroscopy, and electrochemical quartz crystal microbalance in different aqueous salt solutions. Impedance data was interpreted in terms of a model based on a potential drop at the electrode/film interface and a potential drop at the film/solution interface. Quantitative results obtained by the fitting of impedance and ac-electrogravimetry allow to conclude that the main contribution to the potential drop at the film/solution interface is due to the dehydration-hydration process of cations on entering or leaving the film.

Solvent-Independent Electrode Potentials of Solids Undergoing Insertion Electrochemical Reactions: Part III. Experimental Data for Prussian Blue Unde…

2012

Prussian blue-modified electrodes immersed in K+-containing solutions can be used to obtain a solvent-independent redox potential system. On the basis of theoretical modeling of diffusion processes occurring under the conditions of voltammetry of immobilized particles, voltammetric and chronoamperometric data can be combined to obtain solvent-independent electrode potentials for the K+-assisted one-electron reduction of Prussian blue to Berlin white. Data for water, MeOH, EtOH, MeCN, DMS, DMF, and NM are provided.

Identification of electroactive sites in Prussian Yellow films

2013

Abstract Prussian Blue films were electrogenerated on the surface of the transparent ITO electrodes. The electrochemical oxidation to the Prussian Yellow form was investigated by means of in situ voltammetry and vis–NIR spectroscopic techniques. Changes of the whole spectra between 400 and 950 nm were analyzed and three characteristic wavelengths were selected to in situ follow the electrochemical changes of the films. Voltammetric peaks and absorbance derivative curves at these three wavelengths were deconvoluted and were interpreted such as the overlapping of different electrochemical processes. The correlation between these overlapped processes has allowed proposing three different elect…