Potentilla erecta extract as a green and eco-friendly corrosion inhibitor for 360 carbon steel in hydrochloric acid environment

The concentration effect of Potentilla erecta (Tormentil) extract (PEE) as a corrosion inhibitor of 360 carbon steel (360CS) in 1 M of HCl was studied here through weight loss (WL) techniques. potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS). WL data show that PEE is a good corrosion inhibitor. The findings demonstrated that inhibition efficiency (% IE) enhanced with raising PEE concentration, attaining 78.3 % at 50 ppm and finishing at 90.2 % at 300 ppm. Nevertheless, the %IE increases as the temperature rises from 25 to 55 °C, reaching 92.7 % at the greatest concentration of 300 ppm at 55 °C. The adsorption behavior was analyzed, revealing a chemical interaction, with Gibbs free energy calculations (ΔG°) of –53.7 kJmol −1 at 55 °C, indicating favorable adsorption processes and underscoring the thermal stability of the inhibition mechanism. Surface examinations using scanning electron microscopy (SEM) and Atomic force microscopy (AFM) confirmed the formation of a protective layer on 360CS surfaces. Furthermore, it was demonstrated that temperature changes affected both the corrosion rate and the inhibition efficiency, highlighting the thermal stability of the inhibition mechanism. Chemical and electrochemical approaches yielded reliable and agreeable results.