Effect of Hybrid Eco-Friendly Plant Extract for Corrosion Mitigation of Gray Cast Iron in HCL

Abstract

This study investigated the corrosion resistance of gray cast iron in 0.1 M HCl using a hybrid inhibitor system composed of water hyacinth extract and zinc oxide nanoparticles. Electrochemical impedance spectroscopy (EIS), Bode plot analysis, phase angle interpretation, and surface characterization techniques (SEM and EDS) were employed to evaluate inhibitor performance. The results revealed that the combined inhibitors achieved an efficiency of 82.2%, surpassing many previously reported natural inhibitors. Nyquist plots demonstrated a significant increase in charge transfer resistance (Rct), while Bode plots confirmed enhanced impedance at low frequencies and more pronounced capacitive behavior, indicative of a uniform protective film. SEM and EDS analyses further validated the formation of a smoother, compact surface layer with successful adsorption of inhibitor species. These findings corroborate recent reports emphasizing the synergistic benefits of combining organic phytochemicals with inorganic nanoparticles for sustainable corrosion protection Overall, this research highlights the potential of hybrid green inhibitors to deliver long-term, environmentally friendly corrosion prevention in industrial applications.