Abdul M. Sulaiman, Putu H Setyarini, Khairul Anam, Siti Norasmah Surip, Chin Wei Lai
In response to the growing demand for environmentally sustainable corrosion mitigation strategies in acidic industrial environments, a novel bio-hybrid corrosion inhibitor (CI30@CSE) is proposed, in which lauryl betaine (LB) in a commercial CI30 formulation is replaced by Citrus sinensis peel extract (CSE), a renewable agricultural waste-derived component. This work represents one of the first attempts to directly integrate a plant-based extract into an industrial-grade surfactant inhibitor system while preserving high inhibition performance. The hybrid system was systematically evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy, complemented by surface characterization (SEM, AFM) and spectroscopic analyses (FTIR, UV–Vis), together with density functional theory (DFT) and Monte Carlo simulations to elucidate adsorption behavior. CI30@CSE demonstrated a maximum inhibition efficiency of 97.88% at an optimal concentration of 400 ppm, outperforming the conventional CI30 inhibitor (93.76%), thereby confirming that substitution with a biomass-derived component can enhance protection without sacrificing industrial-level performance in 1 M HCl. Surface analysis via SEM and AFM confirmed the formation of denser, smoother, and more coherent protective films on A36 steel, while spectroscopic evidence and molecular simulations revealed strengthened adsorption stability and synergistic molecular interactions between the surfactant matrix and bioactive constituents of CSE. By valorizing citrus peel waste and partially replacing synthetic surfactants with a renewable bio-based alternative, this study contributes to circular chemical design and greener corrosion control strategies, offering a promising pathway toward high-performance, lower-toxicity corrosion inhibitors suitable for sustainable industrial applications. © 2026
Department of Mechanical Engineering, Faculty of Engineering, Brawijaya University, MT Haryono 167, Malang, 65145, Indonesia; Faculty of Applied Sciences, Universiti Teknologi MARA, Selangor, Shah Alam, 40450, Malaysia; Advanced Biomaterials and Carbon Development (ABCD) Research Group, Faculty of Applied Sciences, Universiti Teknologi MARA, Selangor, Shah Alam, 40450, Malaysia; Nanotechnology & Catalysis Research Centre (NANOCAT), Institute for Advanced Studies (IAS), University of Malaya (UM), Kuala Lumpur, 50603, Malaysia
