Electrode gallium

A liquid gallium electrode has similar properties to the mercury electrode (at temperatures above 29°C), but it has a far greater tendency to form surface oxides. 

In order to overcome this problem, a recently developed new approach was used, based on removable metallic liquid top electrodes, i.e. Gallium electrodes. Drops of size smaller than... 

Three cells are connected in series, so the same current passes through each one. The first cell contains silver electrodes in silver nitrate solution, the second copper electrodes in copper(It) sulfate solution, and the third gallium electrodes in gallium(III) chloride solution. In one experiment, 1.500 g of silver is deposited in the first cell. What masses of copper and gallium are deposited in the other cells ... 

A voltaic cell containing a standard Fe /Fe electrode and a standard Ga /Ga electrode is constructed, and the circuit is closed. Without consulting the table of standard reduction potentials, diagram and completely describe the cell from the following experimental observations, (i) The mass of the gallium electrode decreases, and the gallium ion concentration increases around that elec-... 

Lee KT et al (2008) Liquid gallium electrode confined in porous carbon matrix as anode for lithium secondary batteries. Electrochem Solid-State Lett 1LA21-A124... 

Arsenic and antimony are metalloids. They have been known in the pure state since ancient times because they are easily obtained from their ores (Fig. 15.3). In the elemental state, they are used primarily in the semiconductor industry and in the lead alloys used as electrodes in storage batteries. Gallium arsenide is used in lasers, including the lasers used in CD players. Metallic bismuth, with its large, weakly bonded atoms, has a low melting point and is used in alloys that serve as fire detectors in sprinkler systems the alloy melts when a fire breaks out nearby, and the sprinkler system is activated. Like ice, solid bismuth is less dense than the liquid. As a result, molten bismuth does not shrink when it solidifies in molds, and so it is used to make low-temperature castings. 

For liquid electrode metals (mercury, gallium) the determination of the surface tension can be applied. From changes of the surface tension as a function of dissolved adsorbable species the surface coverage... 

Figure 5-47 shows the Mott-Schottky plot of n-type and p-type semiconductor electrodes of gallium phosphide in an acidic solution. The Mott-Schottl plot can be used to estimate the flat band potential and the effective Debye length I D. . The flat band potential of p-type electrode is more anodic (positive) than that of n-type electrode this difference in the flat band potential between the two types of the same semiconductor electrode is nearly equivalent to the band gap (2.3 eV) of the semiconductor (gallium phosphide). 

Fig. 6-47. Mott-Schottky plot of electrode capacity observed for n-type and p-type semiconductor electrodes of gallium phosphide in a 0.05 M sulfuric add solution. [From Meouning, 1969.]...

The same disciission may apply to the anodic dissolution of semiconductor electrodes of covalently bonded compounds such as gallium arsenide. In general, covalent compoimd semiconductors contain varying ionic polarity, in which the component atoms of positive polarity re likely to become surface cations and the component atoms of negative polarity are likely to become surface radicals. For such compound semiconductors in anodic dissolution, the valence band mechanism predominates over the conduction band mechanism with increasing band gap and increasing polarity of the compounds. 

It follows from Eqn. 10-13 that, if a 6sc is much larger than 1 (a 5sc 1, both a and being great), all the photoexcited minority charge carriers will be consumed in the interfacial reaction (ipb = e Iq ). In such a case, the photocurrent is constant at potentials away from the flat band potential as shown in Fig. 10-11 this figure plots the anodic ciirrent of photoexcited dissolution for a gallium arsenide electrode as a function of electrode potential. 

Fig. 10-11. Anodic photoexcited dissolution current of an n-type semiconductor electrode of gallium arsenide as a function of electrode potential in a 0.6 M sulfuric add solution lo - photon intensity = diotocurrent. [From Memming-Kelly, 1981.]...

Fig. 10-17. Polarization curves for cathodic h3 drogen redox reaction on a photoexdted p-type semiconductor electrode of gallium phosphide equilibrium potential of...

Kocha SS, Turner JA (1994) Study of the Schottky barriers and determination of the energetics of the band edges at the n- and p-type gallium indium phosphide electrode electrolyte interface. J Electroanal Chem 367 27-30... 

The reduction of Zn(II) from 1 M NaCl04 in the presence of 1 mM HCIO4 was studied at the dropping gallium and mercury electrodes [42]. Zn(II)/Zn(Ga) waves were obtained after subtraction of the H3O+ reduction current recorded in the absence of Zn(II)/Zn(Ga) couple. 

Kariuki and Dewald [55] have studied current oscillations accompanying reduction of indium(III) and gallium(III) in diluted chloride and nitrate solutions at a dropping mercury electrode. 

If 0 is in the middle range, 0.2 < 0 < 0.8, say, the appropriate isotherm could still be that of Langmuir. This would be likely to be the case for the academic systems of liquid electrodes (mercury and occasionally, liquid gallium). On solid surfaces, the effects of heterogeneity will apply and the appropriate isotherm will be that of Temkin. 

Figure 33 presents dependences of the photoemission current I213 at a p-type gallium arsenide electrode on the quantum energy (for a given potential) and on the potential (for a given quantum energy) in an aqueous solution. Both... 

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