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The physical properties of the electrodes play an important role in determining these quantities. Important properties of the electrodes are: the electrical resistivity, the specific heat capacity (c p), the electrode potential and the hardness. Of course, for technological applications, the cost of the material is also an important factor. [12]
The outcome would be a modified electrode with special new chemical properties in terms of physical, chemical, electrochemical, optical, electrical, transport, and other useful properties. [ 3 ] Chemically modified electrodes and electrodes in general heavily depend on electron transport : a general term for electrochemical processes where the ...
Such rates provide insights into the structure and bonding in the analyte and the electrode. For example, the exchange current densities for platinum and mercury electrodes for reduction of protons differ by a factor of 10 10, indicative of the excellent catalytic properties of platinum. Owing to this difference, mercury is the preferred ...
In between these electrodes is the electrolyte, which contains ions that can freely move. The galvanic cell uses two different metal electrodes, each in an electrolyte where the positively charged ions are the oxidized form of the electrode metal. One electrode will undergo oxidation (the anode) and the other will undergo reduction (the cathode).
During the early development of electrochemistry, researchers used the normal hydrogen electrode as their standard for zero potential. This was convenient because it could actually be constructed by "[immersing] a platinum electrode into a solution of 1 N strong acid and [bubbling] hydrogen gas through the solution at about 1 atm pressure".
Most electrodes work over a limited range of conditions, such as pH or temperature, outside of this range the electrodes behavior becomes unpredictable. The advantage of a pseudo-reference electrode is that the resulting variation is factored into the system allowing researchers to accurately study systems over a wide range of conditions.
To avoid possible ambiguities, the electrode potential thus defined can also be referred to as Gibbs–Stockholm electrode potential. In both conventions, the standard hydrogen electrode is defined to have a potential of 0 V. Both conventions also agree on the sign of E for a half-cell reaction when it is written as a reduction.
An ideal polarizable electrode (also ideally polarizable electrode or ideally polarized electrode or IPE) is a hypothetical electrode characterized by an absence of net DC current between the two sides of the electrical double layer, i.e., no faradic current exists between the electrode surface and the electrolyte.