Corrosion Inhibition of Steel by Various Parts of Rotula Aquatica Plant Extracts in H 2SO 4 Solutions

The corrosion inhibition and adsorption of ethanol extracts of leaves (LV), stems (ST) and roots (RT) of Rotula aquatica plant for mild steel in H 2SO 4 solutions were investigated using conventional weight loss, gasometric techniques, electrochemical polarizations and electrochemical impedance spectroscopy. The results showed that all the three extracts of Rotula aquatica plant performed well as inhibitor for the corrosion of steel in sulphuric acid media and the inhibition efficiencies of the extract follow the trend RT > LV > ST. Inhibition efficiencies increased with increasing concentration of the plant extracts but decreased with the temperature rise for all cases. Both the cathodic hydrogen evolution and the anodic dissolution of mild steel were inhibited, hence the active molecules of all the extracts studied acted as mixed type corrosion inhibitors.