A novel eco-friendly inhibitor of chayote fruit extract for mild steel corrosion in 1 M HCl: Electrochemical, weight loss studies, and the effect of temperature

Abstract

Recently, metal corrosion has become an emerging concern at local and industrial scales, which hamper their conventional production unit. The implication of inhibitors to prevent metal corrosion has gained a huge interest of researchers and industrialists due to its high efficiency, eco-friendly, and economical nature. Herein, the development of a novel and ecofriendly corrosion inhibitor using Sechium edule (chayote) fruit extract is performed. The chemistry of chayote extract was investigated by Fourier transform infrared (FTIR) and Ultraviolet-Visible (UV-Vis) spectroscopies. Anti-corrosive effectiveness of prepared chayote extracts was evaluated using the weight loss method and then electrochemical techniques. Results of potentiodynamic polarization indicated that the chayote extracts were highly effective, with protection efficiencies of 85.72% and 76.82% at the concentration of 2000 mgL−1 of prepared chayote fruit extract in water at pH 3 (CEPH3) and at the original pH 5.2 (CE), respectively. The shift in corrosion potential (Ecorr) was less than 85 mV with respect to the corrosion potential of the blank, revealing that both chayote extracts behaved as a mixed-type of inhibitor. Langmuir adsorption isotherm showed the best fit for the adsorption studies. The free energies (ΔGᵒads) obtained from tests were found to be −53.046 kJmol-1 (CE) and −50.278 kJmol-1 (CEPH3), demonstrating prepared chayote extracts adsorbed onto the metal surface by the chemical adsorption process. Thermodynamic parameters (activation energy, enthalpy, and entropy) were obtained from 303 K to 323 K, indicating that corrosion is spontaneous and endothermic. Outcomes of FESEM, AFM, EDX, and XRD analysis showed that a protective layer was formed on the surface of mild steel (MS) in the presence of chayote extracts.