Cabbage extract as an eco-friendly corrosion inhibitor for X70 steel in hydrochloric acid medium

Abstract

This work explored the feasibility of cabbage extract (CAE) as an environmentally friendly corrosion inhibitor to inhibit the corrosion of X70 steel in 1 M hydrochloric acid solution. Potentiodynamic polarization and electrochemical impedance spectroscopy combined with scanning electron microscope (SEM), atomic force microscope (AFM) were used to inspect anti-corrosion ability of CAE. In addition, X-ray photoelectron spectroscopy (XPS), density function theory (DFT) and molecular dynamics (MD) methods were used to illustrate the anti-corrosion mechanism. The experimental results showed that CAE has excellent protection performance for X70 steel in HCl solution, and its inhibition efficiency could reach 95.37% (298 K), 95.87% (308 K) and 93.36% (318 K) respectively. XPS results also showed that the adsorption is mainly due to the strong coordination bond between Fe-N. This study provides a new window for eco-friendly corrosion inhibitors for pipeline steel that need to be cleaned with acid solutions.