Mitigation effect of natural lettuce oil on the corrosion of mild steel in sulfuric acid solution: chemical, electrochemical, computational aspects

Abstract

The inhibition vigor of natural lettuce oil against corrosion of mild steel (MSt) 1.0 M H2SO4 solutions was investigated using chemical, electrochemical, and computational studies. The anti-corrosion efficacy (%AE) increases with the increase in the amount of doses of lettuce oil and reaches 95.83% from the galvanostatic polarization. The anti-corrosion process was demonstrated by the adsorption of lettuce oil onto the surface of MSt. The adsorption is spontaneous due to the negative signs of free energy of adsorption. The adsorption is subjected to Langmuir isotherm. Lettuce oil inhibits the pitting corrosion of MSt in chloride -containing solutions by transferring the pitting potential to the noble directions. Density functional theory (DFT) and Monte Carlo (MC) simulations were performed on the four components of natural lettuce oil. The adsorption of the inhibitors on the Fe(110) in the solutions is in parallel form. The results obtained from DFT and MC simulations predicted that α-Lactucerol and Lactupicrin give the MC simulations were performed on the four components of natural lettuce oil. The adsorption of the inhibitors on the Fe(110) in the solutions is in parallel form. The results obtained from DFT and MC simulations predicted that α-Lactucerol and Lactupicrin give the highest %AE.