Experimental and theoretical studies of the effect of Ballota hirsuta essential oil on carbon steel corrosion in a molar concentration of HCl
Omar Ou-Ani, Hicham Zgueni, Lahcen Oucheikh, Youssef Youssefi, Mohammed Salah, Abdelmalek Matine, El Houssine Mabrouk, Ahmad Oubair, Driss Chebabe, Mohamed Znini
Abstract
In this research, natural essential oil extracted from Ballota hirsuta (EOBH) was explored as a sustainable and effective corrosion inhibitor for carbon steel (CS) during acid cleaning. EOBH's efficacy as a green inhibitor was assessed in a 1.00 M HCl solution using electrochemical methods such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results demonstrated that EOBH exhibits significant anticorrosion properties, achieving an inhibition efficiency of 95.59 % at a concentration of 2.00 g/L and a temperature of 298 K. The PDP analysis indicated that EOBH functions as a mixed-type inhibitor. EIS data suggested that the inhibitor interacts with the metal surface via charge transfer, forming a protective layer. The presence of a protective film of the inhibitor on CS surface was detected by the scanning electron microscopy with energy-dispersive X-ray (SEM/EDX). Additionally, theoretical studies utilizing density functional theory (DFT) and Monte Carlo (MC) simulations were conducted, aligning well with the experimental findings.