In this paper, the aim was finding the most efficient corrosion inhibitor for mild steel placed in a 0.5M Sulfuric acid. The comparison was implemented between Cysteine (an eco-friendly corrosion inhibitor) and 4 different Ions-Cysteine Inhibitors (Copper- Cysteine, Nickel-Cysteine, Iron-Cysteine, and Cobalt-Cysteine). The solutions were prepared and evaluated while placed with a working electrode of mild steel with a copper rod attached to its end. To determine the best eco-friendly corrosion inhibitors two experiments were implemented: Electrochemical Impedance Spectra, and Linear Polarization. By the end of the experiment it was found that Copper- Cysteine was the most efficient eco-friendly corrosion inhibitor for mild steel with maximum inhibition efficiency of 91%, followed by Nickel-Cysteine with maximum inhibition efficiency of 90.9%. Iron- Cysteine had a maximum inhibition efficiency of 86.04% followed by Cobalt-Cysteine with a maximum inhibition efficiency of 84.3%. These percentages are at highest concentration of the ion, however in this submitted paper the mentioned comparisons will be at moderate concentrations of 25 micro-M ions rather than the 50 micro-M concentration.
Elazab, Hany A. Dr, "Cysteine as an Eco-Friendly Corrosion Inhibitor" (2018). Chemical Engineering. 62.