Eco-friendly corrosion inhibition of copper in NaCl media using Perseana americana extract: Insights from quantum and electrochemical studies

Abstract

Corrosion of copper in saline environments, particularly in 3.5% sodium chloride (NaCl) solutions, poses significant challenges across various industries, leading to substantial economic losses and safety concerns. Traditional corrosion inhibitors, often synthetic and toxic, raise environmental issues that necessitate the exploration of sustainable alternatives. This study investigates the use of Perseana americana extract (PAE) as an eco-friendly inhibitor for copper corrosion, demonstrating an impressive inhibition efficiency of 96.53% at an optimal concentration of 300 mg/L. Electrochemical assessments, including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), reveal that PAE functions as a mixed-type inhibitor, significantly reducing the corrosion current density (icorr) from 3.59 × 10⁻⁵ A/cm2 (without inhibitor) to 1.83 × 10⁻⁵ A/cm2 at 100 mg/L, and further to 0.12 × 10⁻⁵ A/cm2 at 300 mg/L. The adsorption behavior of PAE on the copper surface adheres to the Langmuir isotherm model, indicating monolayer adsorption with a Gibbs free energy of adsorption (ΔGads) of −18.84 kJ/mol, suggesting a predominantly physisorption mechanism. Additionally, Monte Carlo simulations confirm strong interactions between PAE molecules and the copper surface, with the highest adsorption energy recorded for phloretin at −3778.338 kcal/mol, highlighting the extract's potential as a green alternative to conventional inhibitors. This research underscores the viability of utilizing natural plant extracts for effective corrosion control, contributing to more sustainable practices in metal protection.

Keywords

• Copper
• Corrosion
• Perseana americana extract
• Inhibition
• EIS
• DFT