Copper rotating disk electrode

Babu and coworkers [26,27] investigated the copper dissolution in the presence of Fe using a copper rotating disk electrode (RDE). The cathodic reaction was separately studied using a platinum rotating disk electrode, while the overall corrosion process was measured on rotating disks. It was... 

Cu9ln4 and Cu2Se. They performed electrodeposition potentiostatically at room temperature on Ti or Ni rotating disk electrodes from acidic, citrate-buffered solutions. It was shown that the formation of crystalline definite compounds is correlated with a slow surface process, which induced a plateau on the polarization curves. The use of citrate ions was found to shift the copper deposition potential in the negative direction, lower the plateau current, and slow down the interfacial reactions. 

Figure 3a is an illustration of the effect of surface overpotential on the limiting-current plateau, in the case of copper deposition from an acidified solution at a rotating-disk electrode. The solid curves are calculated limiting currents for various values of the exchange current density, expressed as ratios to the limiting-current density. Here the surface overpotential is related to the current density by the Erdey Gruz-Volmer-Butler equation (V4) ... 

This value is based on Cu2+ diffusivities calculated Arvia et al. (A5) from limiting-current measurements at a rotating-disk electrode by, with CuS04 concentrations below 0.1 M. In practical applications (e.g., copper refining or electrowinning) higher Cu2+ concentrations are often required, as is also the case in free-convection limiting-current measurements. 

Shuman and Michael [10] applied a rotating disk electrode to the measurement of copper complex dissociation rate constants in marine coastal waters. An operational definition for labile and non-labile metal complexes was established on kinetic criteria. Samples collected off the mid-Atlantic coast of USA showed varying degrees of copper chelation. It is suggested that the technique should be useful for metal toxicity studies because of its ability to measure both equilibrium concentrations and kinetic availability of soluble metal. 

Shuman, M.S. and Michael, L.C., 1978. Application of the rotated disk electrode to measurement of copper complex dissociation rate constants in marine coastal samples. Environm. Sci. Technol., 12 1069-1072. 

Shuman, M.S., Collins, B.J., Fitzgerald, RJ. and Olson, D.L. (1983) Distribution of stability constants and dissociation rate constants among binding sites on estuarine copper-organic complexes rotated disk electrode studies and an affinity spectrum analysis of ion-selective electrode and photometric data. In Aquatic and Terrestrial Humic Materials (eds Christman, R.F. and Gjessing, E.T.). Ann Arbor Science, Ann Arbor, MI, pp. 349-370. 

Copper salts are reasonably soluble over a wide pH range, but In and Ga salts only exhibit solubilities above ImM at pH < 3 for In and at pH < 1.5 for Ga (82). Rotating disk electrode experiments show that Cu deposits under mass transfer-controlled conditions on Mo, whereas In deposits under kinetic control at room temperature. There are a few reports on electrodeposition of Cu/In or In/Cu stacks for the realization of CIS semiconductor compounds [83, 84). One technologically interesting report from Penndorf et al. [83] describes the use of copper tape as both the substrate and source of Cu for the formation of CuInS2. Indium was electrode-posited on the copper tape in a roll-to-roU process with remarkably high current densities of 150-200 mAcm with the help of thiourea. CeU efficiencies of up to 6% were reported with this approach. 

The successful determination of copper in beer, a complex system that precludes meaningful measurements under silent conditions, opened up the possibility for analysis in even more inaccessible media such as biological samples. Cavita-tional depassivation provides a remarkable enhancement in measured Faradaic currents whilst the increased mass transport due to acoustic streaming lowered the accumulation times below those required for other hydrodynamic voltammetric techniques such as rotating disk electrodes. 

Yang C-C, Cheh HY (1995) Pulsed electrodeposition of copper/nickel multilaycas on a rotating disk electrode I. Galvanostatic deposition. J Electrochem Soc 142 3034—3040... 

The working electrodes were iron, mild steel, duminum, copper, tin or zinc (polished in water with 1200-grit paper), or 2 to 3 pm zinc-electroplated steel. The counter-electrode was a stainless steel plate and the reference electrode a Tacussel KCl saturated calomel (SCE). The rotating disk electrode was an EDI Radiometer monitored with a CTV 101 Radiometer speed control unit... 

Hill, M.R.H. and Rogers, G.T. (1978) Polyethylene glycol in copper electrodeposition onto a rotating disk electrode. 

---