Investigation of Two Organic Corrosion Inhibitor by Density Function Theory and Electrochemical Tests for Prevention the Corrosion of Carbon Steel in ۱M HCl Environment

In this study, the inhibitory effects of two organic corrosion inhibitors, ۲-amino-۵-nitrothiazole (Enheptin) and ۲Aminoethanesulfonic acid on carbon steel ۴۱۳۰ in hydrochloric acid solution were investigated using Tafel polarization tests and Density Function Theory (DFT) (using Gaussian ۰۹W software). The results showed that with increasing the concentration of inhibitors in acidic environment, the percentage of inhibition increases and both organic inhibitors affect the cathodic (hydrogen reduction) and anodic (metal dissolution) reactions so can be classified as mixed inhibitors. With increasing concentration of inhibitors, the inhibitor efficiency of Enheptin was more than ۲-Aminoethanesulfonic acid. The results and parameters derived from the DFT also showed the more chemical and electron affinity of the of the Enheptin atomic orbitals in comparison with ۲Aminoethanesulfonic.