L-cysteine/polydopamine nanoparticle-coatings for copper corrosion protection

•This paper explores the formation of L-cysteine and L-cysteine-dopamine coatings on copper.•Determined that the coatings are effective anti-corrosion coatings.•Optimized equivalent circuits on impedance data to determine values for model parameters.

Polydopamine (PDA) coating on a copper surface was successfully prepared using a two-step process. In the first stage, in order to improve the adhesion of PDA on the copper surface, a self-assembled monolayer of L-cysteine was deposited on a bare copper. Thereafter, the PDA coating was fabricated through the chemical adsorption and auto-polymerization of the dopamine hydrochloride on the L-cysteine-coated copper surface. The inhibitory behavior of L-cysteine and PDA films has been investigated in aqueous 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy. It is demonstrated that the L-cysteine/PDA coating provides significant protection against copper corrosion.