Insight into the anti-corrosion performance of crop waste as a degradable corrosion inhibitor for copper in sulfuric acid medium

Abstract

As an important anti-corrosion method, corrosion inhibitors have attracted extensive attention from researchers. In this study, ultrapure water was used as the solvent, and Abelmoschus esculentus leaf extract (AELE) was prepared using the decoction method, and its corrosion inhibition properties were deeply explored using theoretical and experimental methods. Quantum chemical calculation results show that the four components in Abelmoschus esculentus leaf extract manifest notable corrosion inhibition characteristics. The components demonstrate high binding energy upon adsorption on the Cu (111) surface, demonstrating their effective adhesion to the copper. Electrochemical measurement reveals the remarkable ability of AELE to successfully prevent copper corrosion. AELE demonstrates a corrosion inhibition efficiency of 96.2 % at 600 mg/L. Moreover, even with escalating temperatures, its corrosion inhibition efficacy remains consistently above 90 %. The result from the surface morphology examination indicate that the introduction of AELE into the H₂SO₄ medium substantially diminishes the corrosion extent of the copper. The experimental findings reveal that the adsorption of AELE at the interface between copper and sulfuric acid conforms to the Langmuir adsorption isotherm. The application not only broadens the resource utilization of crop waste, but also brings an innovative and effective corrosion inhibitor to the field of environmentally friendly chemistry.