Cyclic voltammetry gold electrodes

Finally, a thin chromium deposit was plated in situ on a tungsten substrate, then chronopotentiograms were recorded, the analysis of which showed that Cr(II) species was adsorbed, and that adsorbed and dissolved Cr(II) species participated in the reduction process. No adsorption was demonstrated on a vitreous carbon electrode. Cyclic voltammetry was then used at gold, copper, nickel, vitreous carbon and tungsten electrodes (Figure 19). 

Rand DAJ, Woods R. 1972. A study of the dissolution of platinum, palladium, rhodium and gold electrodes in 1 M sulphuric acid by cyclic voltammetry. J Electroanal Chem 35 209-218. 

Figure 3.96 The effect of increasing time of exposure (as indicated) of a gold electrode once-modified with SSBipy to thiophenol on the cyclic voltammetry of horse heart cytochrome t (0.4mM). 20 mM sodium phosphate/0.1 M NaCI04 pH 7.0. Scan rate 20mVs l. From Hill...

The first reports on direct electrochemistry of a redox active protein were published in 1977 by Hill [49] and Kuwana [50], They independently reported that cytochrome c (cyt c) exhibited virtually reversible electrochemistry on gold and tin doped indium oxide (ITO) electrodes as revealed by cyclic voltammetry, respectively. Unlike using specific promoters to realize direct electrochemistry of protein in the earlier studies, recently a novel approach that only employed specific modifications of the electrode surface without promoters was developed. From then on, achieving reversible, direct electron transfer between redox proteins and electrodes without using any mediators and promoters had made great accomplishments. 

The oxidation of hydroxide ion in acetonitrile at copper, silver, gold, and glassy-carbon electrodes has been characterized by cyclic voltammetry. In the absence of bases the metal electrodes are oxidized to their respective cations (Cu+, Ag+, and Au+) at potentials that range from -0.2V vs. SCE for Cu to +1.3 V for Au. At glassy carbon OH is oxidized to 0 - (+0.35 V vs SCE) and then to... 

The redox characteristics, using linear sweep and cyclic voltammetry, of a series of (Z)-6-arylidene-2-phenyl-2,3-dihydrothiazolo[2,3-r][l,2,4]triazol-5(6//)-ones 155 (Figure 24) have been investigated in different dry solvents (acetonitrile, 1,2-dichloroethane, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO)) at platinum and gold electrodes. It was concluded that these compounds lose one electron forming the radical cation, which loses a proton to form the radical. The radical dimerizes to yield the bis-compound which is still electroactive and undergoes further oxidation in one irreversible two-electron process to form the diradical dication on the newly formed C-C bond <2001MI3>. 

The ferrocenyl dendrimers were electrodeposited in their oxidized forms onto the electrode surfaces (platinum, glassy-caibon, and gold) either by controlled potential electrolysis or by repeated cycling between the appropriate anodic and cathodic potential limits therefore the amount of electroactive material electrode-posited can be controlled with the electrolysis time or the number of scans. The electrochemical behavior of films of the polyfeirocenyl dendrimers was studied by cyclic voltammetry in fresh CH2CI2 and CHjCN solutions containing only supporting electrolyte. 

A series of pubKcations was devoted to the electrocatalytic reduction of nitrate by the Eindhoven group [50-54]. On the basis of these works, a comparative study was performed to determine the reactivity of nitrate ions in 0.1 mol dm concentration on eight different polycrystaUine electrodes (platinum, palladium, rhodium, ruthenium, iridium, copper, silver, and gold) in acidic solution using cyclic voltammetry, chronoamperometry, and differential electrochemical mass spectroscopy (DEMS) [50]. 

Figure 4.11 Effect of SAM formation on the cyclic voltammetry of ferrocenylmethyltrimethylam-monium on a polycrystalline gold electrode the supporting electrolyte is 0.5 M H2SO4, with a scan rate of 0.1 V s-1. Curve (a) is the reversible cyclic voltammogram obtained on bare gold, while curves (b)-(d) are obtained on the same electrode with different monolayers (for details see text). The symbols represent theoretical fits to a microarray electrode model. Reprinted with permission from H.O. Finklea, D.A. Snider, J. Fedyk, E. Sabatani, Y. Gafni and I. Rubinstein, Langmuir, 9,3660 (1993). Copyright (1993) American Chemical Society...

Figure 14. Reductive cyclic voltammetry data for selected compounds of environmental interest obtained using a mercury film electrode (on gold) at scan rates of 200 mV/sec in 0.1 M citrate buffer, pH 4.0 and 10% ethanol (v/v) (concentrations of compounds were in the range of 1.8 to 2.3 mg/20 mL)...

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