Study of corrosion inhibition properties of Schinus molle essential oil on carbon steel in HCl

The inhibitory action of Schinus molle L. essential oil was investigated for the corrosion of carbon steel in 1 M hydrochloric acid solution using weight loss, polarization curves, and electrochemical impedance spectroscopy. The inhibition efficiency has increased with the increase of the inhibitor concentration, reaching a value of up to 70% at 2 g/L. The addition of Schinus molle L. (SML) oil essential inhibitors leads to the decrease of both cathodic and anodic currents densities; while the inhibition efficiencies of SML automatically increase to reach a maximum value of 83.74%, which suggests the increase of adsorption ability of target inhibitors to block more electrode surface exposed to the aggressive medium. Double‐layer capacitance C dl values were obtained at the maximum frequency (f max).