Electrochemical nucleation

Microelectrodes for the Determination of Heavy Metal Traces in Physiological Conditions. Hg, Cu and Zn Ions in Synthetic Saliva

“…In particular, the use of Saliva 2 leads to an anodic shift of more than 160 mV with respect to Saliva 3. Literature works [42,43,77,78] suggest the formation of Cu ions as intermediates in the oxidation of metal Cu; these ions are complexed by chloride ions to give CuCl À 2 , hence involving the consumption of only 1 mol of electrons per mol of oxidized Cu; in terms of potential values, our data result in good agreement with those reported in the cited references under analogous experimental conditions. Hence, as suggested by the value of 60 mV for the half-peak width, a one-electron oxidation process can be proposed also in our case, Cl À and SCN À acting as complexing agents for Cu ions in Saliva 2 and 3, respectively.…”

A Study on the Suitability of Carbon Disk Microelectrodes for Trace Analysis of Lead and Copper by ASV

“…In presence of chloride ions, in fact, the copper stripping peak is shifted toward more negative values, owing to the stabilization of the intermediate Cu I species by formation of CuCl Figure 8. In this voltammogram three wellseparated peaks are displayed: a very sharp stripping peak at ¹0.500 V, due to lead in the presence of chloride, a peak at about ¹0.200 V due to the oxidation of Cu to Cu þ [21,22], and a third peak at 0.04 V, which could be attributed to the oxidation of a compound coming from the interaction between lead and copper deposited onto the carbon disk microelectrode. In fact, aqueous solutions containing 0.5 M NaCl and 3 × 10 ¹7 M CuSO 4 provided a single stripping peak at about ¹0.2 V. As stated before, on the basis of electrochemical data alone, we are unable to establish the nature of the compounds responsible of the stripping peak at 0.04 V.…”

Nucleation Process of Indium on a Copper Electrode

“…The dependence of the nucleation process on the metal ion concentration, 24,26,27) the overpotential-dependence of the nucleation, 10,28) the different nucleation processes due to the differences in the structure of electrode surfaces, 29) and the influence of addition of additives on the nucleation 24,30) were studied. The nuclear number density was influenced by supporting electrolytes and their concentrations 27) and increased with an increase of hydrogen ion concentration.…”

“…While the nucleation of Pb on vitreous carbon showed various nucleation processes with overpotential and the nucleation of Au on glassy carbon exhibited instantaneous and progressive process before and after overlapping of particles, respectively. 29) As was discussed earlier, the deposition of indium is done by successive reaction of reactions (26) and (27) as well as reaction (25). Besides In :…”