In this work, electrochemical methods such as Tafel polarization and electrochemical impedance spectroscopy (EIS) were used to study the inhibition efficiency of Nettle leaves hydroalcoholic extract as a green corrosion inhibitor of API 5L carbon steel in 0.5 M H2SO4 solution. The results showed that the inhibition efficiency was increased with increasing the concentration of the extract and the maximum inhibition efficiency in the concentration of 6 g/L was 96%. The negative sign 0 ΔGads absorption of inhibitor on the steel surface was spontaneous and the value 0 ads ΔG represented the physical absorption of the inhibitor which followed the Langmuir isotherm.
