Electrochemical impedance spectroscopy evaluation of nonthermal plasma restoration for ductile metals in cultural heritage artifacts

Despite the large number of studies devoted to understanding the degradation process of ductile metals in cultural heritage, there is still a lack of consolidated protocols for their restoration. Traditional restorations such as chemical cleaning and electrochemical treatments are carried out for the recovery of corroded ductile metals. However, these techniques are usually very aggressive to the metallic surface. For this reason, a cold plasma design is presented to restore ductile metals through the minimum intervention criterion. Lead samples were induced to atmospheric acetic acid corrosion to recreate models of degradation for practical restoration and characterization. The material after plasma treatment was analyzed with different techniques of characterization, including electrochemical impedance spectroscopy. The present work demonstrated the potential of this technique to provide an accurate analysis of its surface.