Rosemary extract inhibitive behavior against mild steel corrosion in tempered 1 M HCl media

Abstract

Recent industrial issues are quite noteworthy for researchers that encourage them to introduce unique approaches to solve them. Among all, corrosion disasters were nominated as the most important ones. Although various routes were introduced for substantial corrosion limitation, inhibits were highly appreciated for worldwide industrial processes. Although the application of inhibitors can substantially prevent the corrosion of metallic substrates, their usage is not far from the limitations. Nowadays, due to the environmental hazards and toxicity of traditional inhibitors, green inhibitors are now replaced. Regarding the special position of plant extracts in the family of green inhibitors, attention should be paid to special features such as renewability and easy access. Undoubtedly, these capabilities have made plant extracts a practical class among all other types. Herein, the Rosemary extract is considered a golden candidate that can be employed as a green corrosion inhibitor in HCl media. The chemistry of Rosemary extract was estimated by Fourier-transform infrared (FT-IR), and Ultraviolet-visible (UV-Vis) spectroscopies. Afterward, the anti-corrosion performance of this inhibitor has been evaluated with electrochemical (potentiodynamic polarization and Electrochemical impedance spectroscopy (EIS)) and weight-loss tests. This study did not neglect the surface studies and the morphology of the surfaces was observed by FE-SEM and AFM techniques. Eventually, the adsorption mechanism has been predicted by thermodynamic studies and adsorption isotherms. Electrochemical outcomes demonstrated that mixed-type inhibition is responsible for 92% corrosion retardation during 6 h steel exposure to 1 M HCl media. The weight-loss studies also had a high convergence with the electrochemical studies and with a slight negligible difference, 800 ppm of rosemary extract prevented 87% of steel corrosion.