Hydrodynamic voltammetry channel electrode

Convection terms commonly crop up with the dropping mercury electrode, rotating disk electrodes and in what has become known as hydrodynamic voltammetry, where the electrolyte is made to flow past an electrode in some reproducible way (e.g. the impinging jet, channel and tubular flows, vibrating electrodes, etc). This is discussed in Chap. 13. 

Hydrodynamic electrodes — are electrodes where a forced convection ensures a -> steady state -> mass transport to the electrode surface, and a -> finite diffusion (subentry of -> diffusion) regime applies. The most frequently used hydrodynamic electrodes are the -> rotating disk electrode, -> rotating ring disk electrode, -> wall-jet electrode, wall-tube electrode, channel electrode, etc. See also - flow-cells, -> hydrodynamic voltammetry, -> detectors. 

Hydrodynamic voltammetry — is a voltammetry technique featuring an electrolyte solution which is forced to flow at a constant speed to the electrode surface. -> mass transport of a redox species enhanced in this way results in higher current. The forced flow can be accomplished either by agitation of the solution (solution stirring, or channel flow), or the electrode (electrode rotation, see -> rotating disk electrode or vibration,... 

As discussed in Section 2 material may reach the electrode surface by diffusion or convection. In cyclic voltammetry at a stationary electrode, and assuming that migration can be neglected, diffusion is the sole form of mass transport. However, material may additionally be transported to the electrode by convection. This genre of voltammetry, where convection is a dominant form of mass transport, is described as hydrodynamic voltammetry. The focus in Section 4 will be on the use of rotating disc and channel electrodes in studies... 

Examples of electrode reaction mechanisms consisting of extensive combinations of E and C steps 42 Hydrodynamic voltammetry 44 Rotating-disc electrodes 46 Channel electrodes 48 Wall jet electrodes 52 Electron-transfer processes 53... 

R. G. Compton, A. C. Fisher, R. G. Wellington, P. J. Dobson, and P. A. Leigh. Hydrodynamic voltammetry with microelectrodes Channel microband electrodes - Theory and experiment, J. Phys. Chem. 97, 10410-10415 (1993). 

The properties and applications of microelectrodes, as well as the broad field of electroanalysis, have been the subject of a number of reviews. Unwin reviewed the use of dynamic electrochemical methods to probe interfacial processes for a wide variety of techniques and applications including various flow-channel methods and scanning electrochemical microscopy (SEM), including issues relating to mass transport (1). Williams and Macpherson reviewed hydrodynamic modulation methods and their mass transport issues (2). Eklund et al. reviewed cyclic voltammetry, hydrodynamic voltammetry, and sono-voltammetry for assessment of electrode reaction kinetics and mechanisms with discussion of mass transport modelling issues (3). Here, we focus on applications ranging from measnrements in small volumes to electroanalysis in electrolyte free media that exploit the uniqne properties of microelectrodes. 

Alden JA, Compton RG (1996) Hydrodynamic voltammetry with channel microbtmd electrodes axial diffusion effects. J Electroanal Chem 404 27—35... 

Aoki K, Tokuda K, Matsuda H (1977) Hydrodynamic voltammetry at channel electrodes. Part... 

Ou TY, Moldoveanu S, Anderson JL (1988) Hydrodynamic voltammetry at an interdigitated electrode array in a flow channel. Pent II. Chemical reaction succeeding electron transfer. J Electroanal Chem 247 1—16... 

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