Effect of Cathodic Polarization on the Depassivation of Oxidized Nickel

Abstract

The dissolution of nickel in sulfuric acid (100 g/L) is studied by cyclic voltammetry using intermediate cathodic polarization between cycles. The main laws of the joint effect of the potential (from –2.0 to ‒0.2 V) and the duration (32–1800 s) of cathode pulses on the metal depassivation are revealed. Anode nickel oxide films are found to disappear during cathodic polarization of the metal as a result of simultaneous processes of reduction and chemical dissolution of oxides in the electrolyte.