The effect of electrodeposited copper sulfide on the cathodic mechanism of copper immersed in synthetic seawater

Abstract

The corrosion behavior of copper electrode in unpolluted and sulfide polluted synthetic seawater (SSW) was carried out. It was demonstrated that the coexistence of sulfide and dissolved dioxygen in seawater leads to an increase in the anodic and cathodic current densities. However, the addition of chitosan polymer as corrosion inhibitor resulted in a significant decrease in the anodic as well as cathodic current densities. The immersion of copper sample in the sulfide-polluted seawater resulted in the formation of a copper sulfide layer on the metal surface. It was observed that the copper sulfide formed on copper foam immersed in sulfide-polluted seawater affects the oxygen reduction reaction (ORR) and, therefore, the entire corrosion mechanism. The copper sulfide film was also obtained on the copper electrodes following electrodeposition method (chronoamperometry). The deposited film increased the diffusion-limiting current suggesting the diffusion-controlled mechanism of the ORR. The presence of chitosan decreased the current density and the rate of oxygen reduction in the synthetic seawater solution.