J. Gregori

Anodic Dissolution of Nickel across Two Consecutive Electron Transfers Calculation of the Ni(I) Intermediate Concentration

The analysis of the electrochemical quartz crystal microbalance and electrochemical impedance spectroscopy results are consistent with a nickel electrodissolution process limited by the passage of Ni(I) to Ni(II), when chloride ions are present in the acid sulfate medium, or by the passage of Ni(II) to Ni 2+ in solution, in absence of chloride. This interpretation allows an explanation of the potential evolution of Fdm/dQ values in both experimental conditions by assuming the formation of a new phase on the electrode surface with a gel-like structure placed between the metal and the solution. Ni(I) surface concentration is calculated from the instantaneous mass/charge Fdm/dQ values.

Nickel Mouldable Electrodes: Mott-Schottky Analysis of Ni(OH)2 Deposited Layers on Nickel Powder-Epoxy Resin Composite Electrodes.

Electrochemical impedance of Ni(OH)2 layers generated on composite Ni-epoxy resin material in basic media are analysed. The formation of α- is favoured in comparison of the β-Ni(OH)2 due to the surface morphology of the composite. The calculated number of charge carrier across Ni(OH)2 from Mott-Schottky analysis of EIS simultaneously depends on the surface morphology of the composite substrate as well as on the method of deposit.

Quartz Crystal Microbalance And Electrical Impedance Characterization Of Nickel Dissolution Process.

Abstract. The anodic nickel dissolution in acid media is analysed by means of EQCM and EIS techniques. The experimental impedance spectra have been fitted to the equivalent circuit which corresponds to two consecutive electron transfers followed by a Ni(II) desorption. That way rate constants and surface concentrations of the Ni(0) and Ni(I) species are obtained. EQCM also provides information about the mechanism of deposition and passivation of nickel as well as the hydrogen evolution.

Electrical Properties Of Poly(Neutral Red) Deposited On Polycrystalline Nickel

Abstract A poly(neutral red) surface-layer has been electrogenerated by means of cyclic voltammetry on nickel surface. Electrical impedance measurements have proved that this polymeric material shows insulating or alternatively an intrinsic conducting character, which depends on the applied potential. This material is a colored lacquer that protects the metallic surface of its anodic dissolution.