Opuntia Ficus Indica Extract as a Corrosion Inhibitor for 304 Stainless Steel in Sulfuric Acid Solution

The addition of the extract of cladodes of Opuntia Ficus Indica (OFI) in an H2SO4 solution to toward the corrosion of 304 stainless steel was studied using weight loss measurement and potentiodynamic polarization curves. A maximum inhibition efficiency of about 91.23% was achieved at 300mg/L. Results reveal that the inhibition efficiency has increased with an increase in extract concentration. By analysis of polarization curves, it is found that OFI acts as a mixed-type inhibitor. The adsorption of OFI is found to obey the Langmuir isotherm. The adsorption free energy for OFI on stainless steel surface reveals a physical adsorption of the inhibitor on the metal surface.