Evaluation of Phytolacca americana L. extract as green corrosion inhibitor for mild steel: a study of the solution phase

Corrosion is undoubtedly the most serious threat to metals. The behavior of this phenomenon is silent and slow, yet continuous, causing the destruction of metal structures and resulting in huge financial losses, as well as environmental pollution. This process is often regarded as a slow behavior, but in environments like oceans, it can be extremely violent and rapid. Researchers are continually seeking solutions to prevent and delay this process. It can be said that in the past decades, chemical corrosion inhibitors have been very popular among researchers and many industries. However, it must be admitted that many of them are toxic and cause great damage to the environment. In recent years, green corrosion inhibitors have been widely studied, and among them, plant-based ones are perhaps the most popular. In this study, Phytolacca americana L. extract was prepared, and its inhibition corrosion efficiency on mild steel was evaluated. For this evaluation, electrochemical impedance spectroscopy (EIS) and polarization test were used. The results showed that the extract is effective in inhibiting corrosion. The results showed that the charge transfer resistance (R_ct) for mild steel decreased significantly with increasing immersion time, but in the presence of the extract, this decrease was surprisingly less.