Insights into the Anticorrosion Performance of Leaf Extract for Copper in Sulfuric Acid Medium.

In this paper, leaves were prepared into a corrosion inhibitor by a pure water extraction method. As a natural plant, leaf extract as a corrosion inhibitor has green features. leaf extract (SLLE) can effectively inhibit the corrosion of Cu in HSO solution. The protective effect on copper in 0.5 mol/L HSO solution was studied by electrochemical measurement, Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and theoretical calculation. These results showed that the maximum corrosion inhibition efficiency (η) of SLLE for copper obtained in the electrochemical measurement at different temperatures is more than 90%. The adsorption of SLLE on copper surfaces conforms to the Langmuir isotherm adsorption model. FTIR and XPS showed the bonding information. SEM and AFM proved that the SLLE can protect the copper from corrosion media. The interaction and inhibition mechanism between the SLLE and copper surface was further revealed at the molecular level by theoretical calculation.