Eco-Friendly Synthesis of Silver Nanoparticles from African Fan Palm (Borassus aethiopum) Leaf Extract for Corrosion Inhibition of Mild Steel in 1 M HCl

A Weight Loss Analysis

Abstract

This study investigates the green synthesis, characterization, and corrosion inhibition behavior of silver nanoparticles (AgNPs) derived from African Fan Palm (Borassus aethiopum) dry leaf extract using aqueous extraction method. The phytochemical constituents of the extract served as natural reducing and stabilizing agents, facilitating the eco-friendly formation of stable, nanosized AgNPs. UV-Visible spectroscopy exhibited a characteristic surface plasmon resonance peak at 283 nm, confirming nanoparticle formation with blue shift, while FTIR spectra revealed that biomolecules present in the extract were actively involved in both silver ion reduction and nanoparticle stabilization through surface adsorption. The corrosion inhibition efficiency of the synthesized AgNPs was evaluated on mild steel in a corrosive medium (1 M HCl) at varying concentrations (100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm, and 400 ppm). The results showed a direct relationship between inhibitor concentration and inhibition efficiency, attaining a maximum efficiency of 80.6%, surface coverage of ≈ 0.81, and a minimum corrosion rate of 0.208 mg cm^-2 h^-1 (2.32 mm/yr) at 400 ppm after 24 hours of immersion. Although the optimum inhibitor concentration was not attained within the studied range, the synthesized AFP-AgNPs demonstrated excellent adsorption and protective characteristics. These findings confirm that Borassus aethiopum leaf extract serves as an effective, sustainable, and eco-friendly source for AgNP synthesis, with promising potential for corrosion inhibition.