The Efficiency of Ecballium Elaterium Extract as Green Inhibitor for Carbon Steel Corrosion in Sulfuric Acid

摘要

The inhibiting influence of Ecballium elaterium extract on the dissolution of carbon steel in 0.5 M sulfuric acid was studied using different methods, including mass loss, electrochemical impedance spectroscopy, potentiodynamic polarization and electrochemical frequency modulation. The tested compound was a mixed-type inhibitor, conforming to Temkin’s adsorption isotherm model and included competitive chemisorption and physisorption mechanisms. The effectiveness of the inhibitor increased with increasing temperature and concentration. The morphology of carbon steel surface and the change on the surface after the inhibition process were studied by Atomic Force Microscopy and Fourier Transforms Infrared Spectroscopy techniques. Some quantum chemical parameters were calculated using the density functional theory to explain which types of phytochemical compounds found in the Ecballium elaterium extract had high efficiency towards the corrosion inhibition of carbon steel in acidic media. All test methods gave corresponding results.