International Journal of Industrial Chemistry (IJIC) A comparative study on the inhibitive effect of Crataegus oxyacantha and Prunus avium plant leaf extracts on the corrosion of mild steel in hydrochloric acid solution Volume 9 (2018), IJIC Issue 3, September 2018 2023 11 17 A comparative study on the inhibitive effect of Crataegus oxyacantha and Prunus avium plant leaf extracts on the corrosion of mild steel in hydrochloric acid solution https://doi.org/10.1007/s40090-018-0154-3 EN R. S. Al-Moghrabi Department of Chemistry, Faculty of Science, Beirut Arab University, Beirut, Lebanon A. M. Abdel-Gaber Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria, 21321, Egypt Department of Chemistry, Faculty of Science, Beirut Arab University, Beirut, Lebanon H. T. Rahal Department of Chemistry, Faculty of Science, Beirut Arab University, Beirut, Lebanon Journal Article 2023 11 17 The inhibitive action of plant leaf extracts, Crataegus oxyacantha (Hawthorn) and Prunus Avium (Sweet Cherry) on the corrosion of mild steel in 0.5 M HCl solution was investigated using open circuit potential-time measurements (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Functional groups of these plants’ leaf extracts and their absorption bands were identified by Fourier transform infrared spectroscopy (FTIR) and Ultra-Violet Spectrophotometer (UV), respectively. The leaf extracts showed good inhibition efficiency in hydrochloric acid solution. Potentiodynamic polarization curves revealed that Crataegus oxyacantha and Purnus Avium plants leaves extracts acted as mixed type inhibitors. Theoretical fitting of different isotherms, Langmuir, Florry–Huggins and the kinetic–thermodynamic models was tested to describe the mode of inhibitors’ adsorption on mild steel surface. UV spectra proved that the inhibiting action takes place through simple physical adsorption of the extracts molecules on mild steel surface.