Evaluation of Idesia polycarpa Maxim fruits extract as a natural green corrosion inhibitor for copper in 0.5 M sulfuric acid solution

Idesia polycarpa Maxim fruits extract (IFE) was investigated as a natural green corrosion inhibitor. The inhibition efficiency obtained from electrochemical impedance spectroscopy (EIS) reached up 90.8% at 298 K, 93.3% at 303 K, and 93.8% at 308 K for 300 mg/L IFE. The results of the polarization test agree with those gained by EIS. The X-ray photoelectron spectroscopy (XPS) analysis was adopted to illustrate the bonding information between Cu and IFE, and the peak of N:Cu bond was detected. The scanning electron microscopy (SEM) observation showed that an effective and protective film was formed on Cu surface, which confirmed the outstanding inhibition capacity of IFE obtained by electrochemical methods. The adsorption of IFE on Cu surface conformed to the Langmuir adsorption model by fitting the EIS data and included both physisorption and chemisorption. Quantum chemical calculation and molecular dynamic simulation were employed to further account for the inhibition mechanism. (C) 2020 Elsevier B.V. All rights reserved.