Effects of Gelatine and Cl^- on a Copper Deposition

Abstract

The decomposition behavior of gelatine in the electrolyte and the effect of the decomposed species on Cu deposition have been investigated. The coeffect of gelatine and Cl^- ion on Cu deposition was also studied. The results obtained are as follows.
1. The morphology of the Cu deposits changed with the molecular weight and concentration of the gelatine. Gelatine decomposition behavior also changed with the molecular weight.
2. The addition of gelatine increased the overpotential of the Cu deposition, while the addition of Cl^- with the gelatine decreased the overpotential.
3. It was found from the impedance analysis using an equivalent circuit that a two-step copper deposition reaction, Cu²⁺→Cu⁺→Cu, proceeds with a hydrogen evolution reaction.