Disk electrodes adsorption

Schmidt TJ, Grgur BN, Behm RJ, Markovic NM, Ross PN. 2000b. Bi adsorption on Pt(l 11) in perchloric acid solution A rotating ring-disk electrode and XPS smdy. Phys Chem Chem Phys 2 4379-4386. 

A standard rotating disk electrode (RDE) setup with a gas-tight Pyrex cell was used for the experiment on CO adsorption and the HOR. A Pt wire was used as counterelectrode. A reversible hydrogen electrode, RHE(t), kept at the same temperature as that of the cell (t, in °C), was used as the reference. All the electrode potentials in this chapter will be referenced to RHE(f). The electrolyte solution of 0.1 M HCIO4... 

In the most common approach, a water-insoluble metaUoporphyrin is deposited on the surface of a rotating disk electrode (RDE) or on the disk of a rotating ring-disk electrode (RRDE Fig. 18.7a) as a film of poorly defined morphology, either by spontaneous adsorption from a solution of the catalyst in an organic solvent or by evaporation of an aliquot of such a solution onto the electrode. It is impossible to know the... 

It was not until 1987, before a second model on electrocodeposition was published by Buelens [37, 58], From experimental observations on the codeposition of particles on a rotating disk electrode (RDE) as a function of current density, rotation speed and bath composition, that could not be explained by Guglielmi, she suggested that a particle will only be incorporated into the deposit if a certain amount of the adsorbed ions on the particle surface is reduced. This is one possible way to account for the field-assisted adsorption, held responsible for the transition between loosely and strongly adsorbed particles in the model of Guglielmi. This proposition yields the probability P(k/K,i) for the incorporation of a particle based on the reduction of k out of K ions, bound to its surface, at current density i... 

A platinum disk electrode was electrolytically platinized in a platinum chloride solution to increase the surface area and enhance the adsorption power. The platinized platinum electrode was then immersed in a solution containing 10 mg ml l ADH. 0.75 mM and 6.2 mM NAD. After sufficient adsorption of these molecules on the electrode surface, the electrode was transferred into a solution containing 0.1 M pyrrole and 1 M KC1. Electrochemical polymerization of pyrrole was conducted at +0.7 V vs. Ag/AgCl. The electrolysis was stopped at a total charge of 1 C cm 2. An enzyme-entrapped polypyrrole membrane was deposited on the electrode surface. 

Bhugun, I. and Anson, F. C. (1997). A generalized treatment of the dynamics of the adsorption of Langmuirian systems at stationary or rotating disk electrodes, J. Electroanal. Chem., 439, 1-6. 

Figure 5.11 Desorption of a SAM of dodecanethiolate from a rotating Cu-disk electrode, (a) Current measured at the Cu electrode, (b) Current measured at a Au-ring electrode indicating oxidative adsorption of a thiol. Electrolyte 0.1 NaOH + H2O (5%) in methanol. Reproduced with permission from Ref [165].

Fig. 8 Catalysis of O2 reduction at a ring-disk electrode in contact with an aqueous 0.5 M H2SO4 solution, the graphite disk (EPGE) being modified by adsorption of a biscobalt diporphyrin, C02ETE4. (a) Disk current, solution saturated with oxygen, p02 = 1 atm rotation rate 100 r min scan rate ...

The Frumkin epoch in electrochemistry [i-iii] commemorates the interplay of electrochemical kinetics and equilibrium interfacial phenomena. The most famous findings are the - Frumkin adsorption isotherm (1925) Frumkin s slow discharge theory (1933, see also - Frumkin correction), the rotating ring disk electrode (1959), and various aspects of surface thermodynamics related to the notion of the point of zero charge. His contributions to the theory of polarographic maxima, kinetics of multi-step electrode reactions, and corrosion science are also well-known. An important feature of the Frumkin school was the development of numerous original experimental techniques for certain problems. The Frumkin school also pioneered the experimental style of ultra-pure conditions in electrochemical experiments [i]. A list of publications of Frumkin until 1965 is available in [iv], and later publications are listed in [ii]. 

The strong chemical interaction of a lipid thiol monolayer developed on a gold disk electrode yields a structure resembling a biological membrane. The blocking ability of various substances was tested for the cyclic voltametry redox reaction of [Fe(CN)g]3-ions, upon adsorption on the thiol monolayer. This was applied to measure the threshold concentrations for detection of various odor substances. The order of response shown in series 30 was the same as the one followed by the human olfactory sense, pointing to... 

Although a major advantage of rotating disk electrode techniques, compared to stationary electrode methods, is the ability to make measurements at steady state without the need to consider the time of electrolysis, the observation of current transients at the disk or ring following a potential step can sometimes be of use in understanding an electrochemical system. For example the adsorption of a component. 

---