Withania somnifera extract (WSE) as eco-friendly corrosion inhibitor for Al in acidic solutions: Experimental and mathematical analyses

This study investigates the anticorrosion behavior of Withania somnifera extract (WSE) as a green inhibitor for Al in hydrochloric acid (HCl) solutions.The preparation of the plant extract involved extraction by dichloromethane.Mass loss measurements and electrochemical techniques were used to evaluate its efficacy.Results indicate a significant reduction in the corrosion rate of Al, with inhibition efficiency increasing with extract concentration, achieving up to 81.16% at 300 ppm.The adsorption behavior was analyzed, revealing a combination of physical and chemical interactions, with Gibbs free energy calculations indicating favorable adsorption processes.Surface examinations using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed the formation of a protective layer on Al surfaces.Additionally, temperature variations were shown to influence the corrosion rate and inhibition efficiency.Additionally, machine learning techniques showed that Gradient Boosting Regression (GBR) outperformed K-Nearest Neighbors (KNN) and Support Vector Regression (SVR), with R 2 values from 0.923 to 0.982.Feature importance analysis indicated that inhibitor concentration was a key predictor across datasets.These findings suggest that Withania somnifera is a promising eco-friendly alternative for corrosion inhibition in acidic environments, promoting the use of natural compounds in industrial applications.