Reduction of copper ions release by a novel ecofriendly electropolymerized nanolayer obtained from a natural compound (carvacrol)

•Carvacrol (Carv) is a natural compound, component of origanum essential oil.•Cu corrosion in chloride medium is inhibited by treatments with Carv.•A highly protective layer was obtained by electropolymerization of Carv (polyCarv).•Carv adsorptive layer was not protective enough to inhibit corrosion.•PolyCarv shows ether bonds, reduces Cu ions release and is ecofriendly.