Corrosion inhibition effect of sycamore leaf extract on copper in H2SO4 solution

Abstract

Utilizing natural plants as a source material for the extraction of corrosion inhibitors aligns with the principles of ecologically sustainable development. This study investigated the corrosion inhibition effects and mechanisms of sycamore leaf extract (SLE) on copper in a 0.5 M sulfuric acid solution. The electrochemical results revealed that sycamore leaf extract showed significant corrosion-inhibiting properties against copper corrosion in a 0.5 M sulfuric acid solution, with greater corrosion to be observed at elevated temperatures. At 298 K, the corrosion current density of copper in 300 mg/L SLE solution is 4.35 μA/cm2, which is two orders of magnitude lower than that in blank solution (123 μA/cm2). The adsorption isotherm demonstrated that the adsorption type between the copper/solution interface at each temperature was comprised of physicochemical interactions. Functional groups and chemical components of SLE and soaked copper samples were characterized using FTIR, UV-Vis, and XPS. The presence of the Cu-N bond on the Cu surface after dipping into the SLE solution indicated that SLE created a shield-like layer that safeguards the copper. Moreover, molecular dynamics (MD) simulation revealed that strong multiple anchor adsorption of SLE molecules because of the existence of N, O atom.