Inhibition effect of Bombax ceiba flower extract as green corrosion inhibitor of mild steel in 0.5 M H2SO4 medium

Abstract

The search for low cost, biodegradable and easily available green corrosion inhibitors against metal corrosion has incited the study of the inhibition potentiality and adsorption behaviour of Bombax ceiba flowers extract for mild steel in 0.5 M H2SO4 medium. Weight loss, potentiodynamic polarization and scanning electron microscopy techniques were employed for the analysis. Inhibition efficiency and various thermodynamic parameters such as activation energy (Ea), adsorptive equilibrium constant (Kads) and free energy of adsorption (∆Gads) were obtained using weight loss measurements data. Bombax ceiba flower extract constituents inhibited the mild steel corrosion process by formation of protective layer on surface follows the Langmuir adsorption isotherm. The results of electro-chemical analysis directed the mixed-type behaviour of investigated inhibitor. Weight loss measurements showed the 90.84 % inhibition efficiency of Bombax ceiba flower extract at optimum concentration of inhibitor at 298 K. SEM analysis shows the remarkable upgraded surface of the mild steel strips with the inhibitor in 0.5 M H2SO4 medium.