Bismuth oxide electrodes

Bismuth electrode (or bismuth-bismuth oxide electrode) -> pH-sensitive electrodes... 

In their pioneering work on the formation of photoelectrochemically active metal sulfides by oxidation of the parent metal electrode. Miller and Heller [29] reported the anodic formation of polycrystalline Bi2S3 on a bismuth metal electrode in a sodium polysulfide cell, wherein this electrode was used in situ as photoanode. When a Bi metal electrode is anodized in aqueous sulfide solutions a surface film is formed by the reaction... 

Herteto E, Rodes A, Perez JM, Feliu JM, Aldaz A. 1995d. CO adsorption and oxidation on Pt(lll) electrodes modified by irreversibly adsorbed arsenic in sulfimc-acid medium— Comparison with bismuth-modified electrodes. J Electroanal Chem 393 87-96. 

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 ... 

There is a need to develop new types of oxide electrodes for reactions of technological importance with emphasis on both high electrocatalytic activity and stability. For example, pyrochlore-type oxides, e.g. lead or bismuth ruthenates, have shown excellent catalytic activity for the oxygen evolution and reduction reactions and should be further investigated to elucidate the reasons for such high activity. The long term stability of such ruthenate electrodes is questionable, however. 

B.A. Boukamp, I.C. Vinke, K.J. de Vries and A.J. Burggraaf, Surface oxygen exchange properties of bismuth oxide-based solid electrolytes and electrode materials. Solid State Ionics, 32/33 (1989) 918-923. 

We have recently shown that a bismuth oxide ring electrode may be used as a sensitive potentiometric electrode for measuring small local changes in pH at the disc surface [17]. The electrode is particularly sensitive near pH 7 and fluxes as low as lpmolcm 2s 1 can be measured, providing that stringent precautions are taken to exclude the buffering effects of adven-titous C02. 

The value of m is dependent upon the pH of the solution. If m 0, then redox reaction involves the incorporation and expulsion of protons during the redox reaction and this can be measured by a pH-sensitive bismuth oxide ring electrode [18,19]. In the special case when the ring electrode is a potentiometric sensor with a low exchange current density, such as the bismuth oxide sensor for pH [18,19], the ring electrode reaction does not significantly perturb the radial concentration profile of the disc product across the ring, and a different collection efficiency, termed the detection efficiency. 

The exact form of the proton transients seen at the ring is determined by the degree of protonation of the L centers and their ability to act as a buffer, mopping up the protons produced in the redox reaction. This is determined by the pATaS for deprotonation of the various protonated forms of L. Quantitative analysis of the proton transients observed at the bismuth oxide ring electrode enabled these values to be determined as... 

Nickel-based positive electrode made of 3 to 95 wt% NiOH balance consists of either nickel powder, cobalt powder, or carbon powder, possibly in combination. Carbon-based negative electrode made of 10 to 95 wt% carbon, with balance consisting of at least one metal oxide from group of bismuth oxide, iridium oxide, cobalt oxide, iron oxide, and iron hydroxide, and hydride from Groups IIIA, IIIB, IVA, IVB, VB, VIB, VIIB,andVIIIB. 

Kadara, R.O. and Tothill, I.E. (2008) Development of disposable bulk-modified screen-printed electrode based on bismuth oxide for stripping chronopotentiometric analysis of lead(II) and cadmium(II) in soil and water samples. Anal. Chim. Acta, 623, 76. 

Khairy, M., Kadara, R.O., Kampouris, D.K. and Banks, C.E. (2010) Disposable bismuth oxide screen printed electrodes for the sensing of zinc in seawater. Electroanalysis, 22, 1455. 

Use of bismuth oxide as an inexpensive additive to the zinc electrodes to improve the capacity retention and the cycle life of the cells. ... 

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