Effective steel alloy surface protection from HCl attacks using Nepeta Pogonesperma plant stems extract

Notwithstanding the wealth and convenience that have been brought by fast-growing technologies globally, they have endangered human and environmental health. The potential rescue missions demand innovative ideas and hard work which is the center of countless research in recent years. Influenced by this motivation, this study employed a new plant extract-Nepeta Pogonesperma extract (NPe)-for the first time in the corrosion-related studies as an inhibitive species in the aggressive environment (1 M HCl) for the mild steel (MS). Several tests for surface and corrosion evaluations were employed including FE-SEM, AFM, EDAX, FT-IR, GIXRD, Raman, electrochemical spectroscopy (EIS), and potentiodynamic polarization (PP). FE-SEM showed that despite maximum surface corrosion attack taking place for the no-inhibitor-containing sample, after inclusion of NPe, significant enhancement was observed in the surface smoothness. This was then affirmed by AFM analysis. The FT-IR results affirmed the existence of functional groups as well as bonds of NPe molecules on the MS surface. UV-Vis results were indicative of C=C along with C=O group existence. Raman spectroscopy test demonstrated the existence of some NPe structure's functional groups. EIS outcome correlated the enhancement of NPe concentration to the improvement of the corrosion-preventive capacity of the surface. Also, it revealed that the maximum inhibition efficiency (92%) was obtained for the solution doped with 1000 ppm of the inhibitive agent at the end of the 5 h exposure period. The PP results bestowed the minimum value of i(co)(rr) to the sample confirmed by the EIS test.

Automated summary

Despite the wealth and convenience brought by rapidly advancing technologies globally, they have posed threats to human and environmental health. This study utilized a new plant extract as an inhibitive species for mild steel corrosion, conducting various tests to determine the optimal concentration for inhibitive efficiency.