Chemical and electrochemical investigation of poly (vinyl alcohol) cobalt nanoparticles composite as corrosion inhibitor for soft-cast steel in 1 M HCl medium

Abstract

A novel polyvinyl alcohol/cobalt nanoparticle (Co-PVA) nanocomposite was synthesized and thoroughly characterized using a range of analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The SEM analysis revealed that the cobalt nanoparticles within the composite possess a spherical morphology. Additionally, both XRD and SEM results confirmed the successful incorporation of elemental cobalt into the polymer matrix. The effectiveness of the Co-PVA nanocomposite as a corrosion inhibitor for soft cast steel (SCS) in a 1 M HCl solution was evaluated through a series of experiments, including weight loss measurements, electrochemical testing. The findings indicate that the Co-PVA nanocomposite serves as an efficient corrosion inhibitor for SCS. Notably, the composite achieved a maximum inhibition efficiency of 96.9 at 303 K, as determined by weight loss measurements. Electrochemical analysis through potentiodynamic polarization revealed that the Co-PVA nanocomposite acts as a mixed-type inhibitor, influencing both anodic and cathodic reactions. The adsorption behavior of the composite onto the SCS surface was found to follow the Langmuir adsorption isotherm, suggesting a uniform and strong interaction between the inhibitor and the metal surface. The formation of a protective film by the Co-PVA nanocomposite on the SCS surface was corroborated by AFM, SEM, EDS, XPS, and water contact angle measurements, highlighting the composite's potential as a robust corrosion inhibitor in acidic environments.