Eco-friendly corrosion mitigation for copper in desalination acid cleaning using plant extract

Addressing copper corrosion in acidic cleaning procedures in the desalination industry is crucial for preserving efficiency, assuring water quality, and reducing environmental effect. Traditional procedures can offer environmental concerns, necessitating the quest for creative, eco-friendly solutions. This work provides a very effective, natural method to corrosion control by studying the inhibitory effects of Acacia farnesiana extract (AFE) for copper corrosion in 1 M HCl solution. To assess AFE's anticorrosion effectiveness, we used extensive procedures, including weight loss (WL) and sophisticated electrochemical techniques (EIS and polarization). The extract achieved the highest inhibitory efficiency at 97.4% (EIS), 96.3% (polarization), and 94.1% (weight loss). The novelty of this work lies in the identification of long-chain fatty acids (Linoleic and Oleic acids) as the primary drivers of inhibition. HPLC analysis confirmed a high concentration of C18 unsaturated fatty acids, which provide a dual-action defense: chemical anchoring via carboxyl groups and physical shielding via a hydrophobic alkyl-chain barrier. This molecular synergy results in a superior inhibition efficiency of 97.4% in 1 M HCl. According to our investigation, AFE offers maximum protection by acting in the forming of mixed-type corrosion inhibitor. In order to provide a solid knowledge of the inhibitory mechanism, we also investigated the impact of temperature and identified pertinent thermodynamic factors. The efficient adsorption behavior of AFE onto the copper surface, creating a protective barrier, is visually validated by surface examinations utilizing electron microscopy (SEM), energy dispersive X-ray (EDS) and Fourier Transform Infrared (FT-IR) spectroscopy analysis. Quantum chemical calculations showed that the four primary fatty acids in AFE can operate as electron donors and so assist in the creation of a protective AFE covering on the copper surface. This study highlights AFE's potential as an effective, eco-friendly remedy for industrial corrosion problems.