Electrochemical Behaviour of Aluminum in Artificial Seawater in the Presence of Artemisia annua L.

Abstract

This study investigated the use of Artemisia annua L. aqueous extract as a corrosion inhibitor for aluminum in artificial seawater using cyclic voltammetry (CV), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) measurements. The surface film formed on the Al in the presence of A. annua was analyzed using Fourier-transform infrared (FTIR) spectroscopy. Electrochemical results showed that A. annua is a mixed type inhibitor of Al corrosion with predominantly anodic action and is changing the electrochemical behavior of Al in artificial seawater by inhibiting dissolution processes. The inhibition efficiency of ∼91% was attributed to the formation of a homogenous multilayer composed of phenolic acids. According to the results of FTIR analysis, the adsorption was established through the carboxyl group of phenolic acids, where stabilization of the adsorption layer was achieved through interactions between aromatic rings and the aliphatic chains. The adsorption mechanism obeyed the Freundlich isotherm model and El-Awady kinetic-thermodynamic models and referred to physical adsorption (ΔG_ads = 18.83 ± 2.34 kJ mol⁻¹).