Sonoelectrochemistry, cells

To conclude the discussion on quasi-reversible reactions, we now direct our attention to sonoelectrochemical reactions on diamond electrodes [107-109], In sonoelectrochemistry, power ultrasound is applied to electrochemical cell, causing forced convection in the electrode-electrolyte system. As a result of the enhanced mass transfer, non-steady-state potentiodynamic curves with current peak turn to steady-state curves with a limiting current plateau (Fig. 21). Notice a significant increase in the current. It must be emphasized that in sonoelectrochemistry electrode materials are exposed to extreme conditions with mechanical strains induced by pressure waves and cavitation-induced liquid jets strong enough to cause severe erosion. Diamond withstands the sonoelectrochemical conditions perfectly. This opens up fresh possibilities for efficient electrolyses and electroanalyses with diamond electrodes. 

A cell for sonoelectrochemistry with a variable distance between the electrode and the ultrasonic horn has been published [91]. 

The simultaneous application of ultrasonic irradiation to an electrochemical reaction which has been termed sonoelectrochemistry has been shown to produce a variety of benefits in almost any electrochemical process. These include enhanced chemical yield in electrosynthesis and the control of product distribution improved electrochemical efficiency in terms of power consumption, improved mixing, and diffusion in the cell minimization of electrode fouling accelerated degassing and often a reduction in the amount of process-enhancing additives required. In a major chapter devoted to this topic, Suki Phull and Dave Walton have attempted to cover the majority of applications of ultrasound in electrochemistry including electrochemical synthesis, electroanalytical chemistry, battery technology, electrocrystallization, electroinitiated polymerization, and electroplating. 

In sonoelectrochemistry, electrodes are exposed to strong ultrasound. An ultrasound transducer (so-called ultrasonic horn) is introduced, preferably opposite to the electrode. There are also proposals where the electrode itself acts as ultrasonic transducer, a sonoelectrode. Sonoelectrochemistry is not a part of thermoelectrochemistry, but temperature effects make up a big part of the actions caused in a sonicated cell. Thereby, the subject may be considered to be some kind of an interlink on the way to modem thermoelectrochemistry. Some arrangements and results are depicted in Fig. 3.11. 

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