Oxide electrodes, types

Electrodes. A number of different types of nickel oxide electrodes have been used. The term nickel oxide is common usage for the active materials that are actually hydrated hydroxides at nickel oxidation state 2+, in the discharged condition, and nickel oxide hydroxide [12026-04-9] NiO OH, nickel oxidation state 3+, in the charged condition. Nickelous hydroxide [12034-48-7J, Ni(OH)2, can be precipitated from acidic solutions of bivalent nickel... 

Because the sdv er oxide electrode is slightly soluble in the potassium hydroxide electroltye the separator is of a barrier type to minimize silver... 

Metal oxide electrodes are also of the second type. A well known example is a rod of antimony coated with Sb203 (or bismuth with Bi203), which can function as a pH electrode33 ... 

Various other semiconductor materials, such as CdSe, MoSe, WSe, and InP were also used in electrochemistry, mainly as n-type photoanodes. Stability against photoanodic corrosion is, naturally, much higher with semiconducting oxides (Ti02, ZnO, SrTi03, BaTi03, W03, etc.). For this reason, they are the most important n-type semiconductors for photoanodes. The semiconducting metal oxide electrodes are discussed in more detail below. 

Fig. 10-12. Anodic photoexcited current of oxidation of water mole cules to produce oxygen gas as a function of electrode potential of an n-type tungsten oxide electrode in an acidic solution X. = wave length of photons. [From Butler, 1977.]...

In nonaqueous solutions, the usable potential range is large, on the order of 5 V. This potential range allows a wide variety of oxidations and reductions to be examined. Some typical values on different types of film electrodes are reported in Table 11.2 [75]. The electrolysis of several organic compounds in these solvents has been characterized. A general observation is that the tin oxide electrode appears more suited to studies of reduction processes than of oxida-... 

Metal-metal oxide electrodes, which are strongly influenced by pH, can be regarded as relatives of MMOs. Two types of metal-metal oxide reference electrodes were tested in concrete some years ago [25], but they are scarcely in use today. 

Figure 4.39 Schematic representations of the various types of electrode surfaces for which protein voltammetry is commonly observed (a) a metal electrode modified with an XY SAM (b) a metal oxide electrode (c) an electrode modified with a surfactant layer in which protein molecules are embedded (d) a pyrolitic graphite edge electrode, often used in conjunction with mobile co-adsorbates such as aminocyclitols. Reprinted from Uectrochim. Acta, 45, F.A. Armstrong and G.S. Wilson, Recent developments in faradaic bioelectrochemistry, 2623-2645, Copyright (2000), with permission from Elsevier Science...

Fig. 1.19. Transparent conducting oxide electrodes in different types of thin film solar cells. TCO contacts are given at the bottom of each structure. The bottom most row indicates the doping type of the semiconductor, which is in contact to the TCO...

Oxide electrodes have been used as reference electrodes in cryolite-alumina melts for the measurement of the oxygen-ion concentration. Thus, Rolin et al. [93-95] used galvanic cells of the following types ... 

Surface redox reactions — or surface -> electrode reactions, are reactions in which both components of the -> redox couple are immobilized on the electrode surface in a form of a -> monolayer. Immobilization can be achieved by means of irreversible -> adsorption, covalent bonding, self-assembling (- self-assembled mono-layers), adhesion, by Langmuir-Blodgett technique (- Langmuir-Blodgett films), etc. [i]. In some cases, the electrode surface is the electroactive reactant as well as the product of the electrode reaction is immobilized on the electrode surface, e.g., oxidation of a gold, platinum, or aluminum electrode to form metal oxide. This type of electrode processes can be also considered as surface electrode reactions. Voltammetric response of a surface redox reaction differs markedly from that of a dissolved... 

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