Evaluation of Aronia Pomace Extract as a Green Corrosion Inhibitor

In this study, the effectiveness of Aronia pomace extract as an environmentally friendly corrosion inhibitor for carbon steel in 1 M HCl was investigated. Electrochemical measurements, including electrochemical impedance spectroscopy (EIS) and polarization studies, revealed a significant reduction in the corrosion rate in the presence of the extract, with a maximum inhibition efficiency of 96.7% at the optimal concentration of 100 ppm after 24 hours. EIS results indicated an increase in charge transfer resistance over time for all tested concentrations and the formation of a stable protective film on the steel surface. Polarization measurements suggested that the extract acts as a mixed-type inhibitor, with a predominant effect on the cathodic reaction. Scanning electron microscopy (SEM) analysis showed a smooth and compact surface for the inhibited samples, while contact angle measurements confirmed increased compaction of the organic protective layer over time. X-ray photoelectron spectroscopy (XPS) identified the presence of organic functional groups from phytochemicals in the extract on the steel surface, confirming the adsorptive protection mechanism. These results demonstrate that aronia extract is an efficient, environmentally friendly inhibitor of carbon steel corrosion in acidic media, with potential applications in industrial processes and green metal protection technologies.