Adsorption and corrosion inhibition characteristics of strawberry fruit extract at steel/acids interfaces: experimental and theoretical approaches

The adsorption and corrosion inhibition behavior of strawberry fruit extract at steel/1 M HCl and steel/0.5 M H₂SO₄ interfaces were investigated using gravimetric and electrochemical methods at 25 and 60 °C. Results obtained showed that the extract inhibited the acid-induced corrosion of mild steel which was more pronounced in HCl than H₂SO₄ medium. Inhibition efficiency increased with increase in the concentration of the extract but decreased with increase in temperature. The potentiodynamic polarization studies revealed that the extract functions as mixed-type inhibitors. The inhibition was assumed to occur via adsorption of the components of the extract on the mild steel surface which can be approximated by Langmuir adsorption isotherm model. Quantum-chemical calculations and molecular dynamics simulations have been used to provide insights into the mechanism of interaction of ascorbic acid as a major constituent of the extract with mild steel.