Sunflower petals extract as a green, eco-friendly and effective corrosion bioinhibitor for carbon steel in 1M HCl solution

Annually metal corrosion leads to many financial losses. In the current study for the first time, sunflower petals extract (SFPE) as a cheap and environmentally safe anti-corrosion agent for carbon steel in acidic media is introduced. The results of polarization and electrochemical impedance spectroscopy indicated that SFPE acts as a suitable anti-corrosion agent with an efficiency of ∼75–79% at the low concentration of inhibitor. Surface morphologies of carbon steel in the presence and absence of inhibitor examined by scanning electron microscopy (SEM) revealed that in the presence of the SFPE, less damage occurs on the alloy surface. Temperature studies showed that by the increase of temperature the corrosion rate increases, and the positive values for enthalpy changes confirmed that the process of iron dissolution is endothermic. The isothermal studies showed that the adsorption of SFPE on the surface of steel was best fitted by the Langmuir isotherm.