Effect of Anise Extract as Green Corrosion Inhibitor Carbon Steel in CO2-Containing Salt

The corrosion and corrosion inhibition of CK10 carbon steel in CO2-saturated 3% NaCl solution by anise extract (AE) dissolved in ethylene glycol (EG) was studied using polarization curves، electrochemical impedance spectroscopy (EIS) and surface analysis (AFM) methods. Inhibition efficiency increased with increase in AE concentration and temperature. The data suggest that AE functioned as inhibitor via a mixed-inhibitor mechanism and the inhibition process is attributed to the formation of a chemically adsorbed film of AE and EG on the surface of the metal via its polycentric adsorption sites. Thermodynamic adsorption parameters of studied inhibitor were calculated using the Langmuir adsorption Isotherm. Morphological studies of the carbon steel electrode surface were undertaken by atomic force microscopy (AFM).