Investigating Xanthium spinosum extract as an eco-friendly corrosion inhibitor for Aluminium in acidic environments: A green approach to metal protection

Abstract

The impact of Xanthium spinosum (Xs) extract on the dissolution of aluminium (Al) in hydrochloric acid (HCl) solution was assessed through various methods, including gravimetric (GM) analysis, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation spectroscopy (EFM). The surface morphology of the corroded Al was analyzed using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Gravimetric measurements indicated that a concentration of 300 ppm of Xs at 298 K resulted in an inhibition efficiency of 93.1 %. The adsorption of Xs onto Al conformed to the Langmuir isotherm model, while PDP analysis classified Xs as a mixed-type inhibitor. EIS data displayed a capacitive loop at high frequencies and an inductive loop at low frequencies. The reliability of EFM data was supported by CF² and CF³ values. The inhibition mechanism was clarified through experimental findings, along with AFM and XPS analyses, confirming Xs as an effective and environmentally friendly corrosion inhibitor.