Curcumin Decorated Silver Nanoparticles as Bioinspired Corrosion Inhibitor for Carbon Steel

Background: Curcumin-stabilized silver nanoparticles (Cur-AgNp) were synthesized by a facile chemical method. The synthesized AgNp was, for the first time, used as a bio-derived corrosion inhibitor for carbon steel in the 1M sulphamic acid medium. Methods: The electrochemical studies via impedance spectroscopy, potentiodynamic polarization, and surface analysis are reported in the communication. The maximum inhibition efficiency of 92.87% was obtained at 800 mgL^-1. Results: The impedance measurements revealed an elevation in the polarization resistance with growth in the inhibitor concentration, which supports the adsorption and inhibition behavior of Cur-AgNp on the steel surface. The inhibitor functioned by adsorption on the steel surface and obeyed the Langmuir kinetic-thermodynamic isotherm with a mixed mode of physical/ chemical adsorption. The potentiodynamic polarization study revealed cathodic predominating behavior. Conclusion: The SEM analysis depicted the development of a protective inhibitor film on the steel substrate, and FTIR-ATR analysis of the inhibited steel surface supported the adsorption of the corrosion inhibitor on the metallic surface.