Eco-friendly synthesis of cobalt nanoparticles from Erythrina crista-galli leaves for enhanced anticorrosive performance

Corrosion of mild steel in acidic environments poses a significant challenge to industrial sustainability due to its economic and structural implications. Conventional corrosion inhibitors often involve toxic and non-biodegradable chemicals, leading to environmental concerns. To address this, the present study explores an environmentally benign method for the synthesis of cobalt nanoparticles (CoNPs) using Erythrina crista-galli leaf extract, which acts as a natural reducing and stabilizing agent. The novelty of this work lies in the green synthesis of CoNPs with enhanced anticorrosive activity, which surpasses traditional methods by eliminating hazardous reagents and minimizing environmental impact. Synthesis parameters such as extract concentration, pH, precursor-to-extract ratio, reaction temperature, and time were optimized to achieve nanoparticles with improved stability, morphology, and crystallinity. The synthesized CoNPs were thoroughly characterized using UV–visible spectroscopy, FTIR, DLS, Zeta potential analysis, SEM–EDX, and XRD, confirming the formation of well-dispersed nanoparticles with controlled size and shape. Electrochemical studies using potentiodynamic polarization and weight loss techniques revealed a maximum corrosion inhibition efficiency of 90.08% for CoNPs in 0.5 M HCl solution, demonstrating their strong barrier effect on steel surfaces. These findings underscore the potential of green-synthesized CoNPs as a sustainable and highly efficient alternative to synthetic corrosion inhibitors for industrial applications.

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