Corrosion inhibition of X60 steel in 1 M HCl by the hydro-methanolic extract of Opuntia ficus-indica L.: gravimetric and electrochemical investigation

• S. Chouai¹, A. Kalla², W. Azabi³, N. Gherraf³, A. Zellagui⁴, H. Taibi³, C. Zahaf³, S. Hameurlaine⁵ and A. Ouahab⁶

¹ Laboratory for Assessing Quality of Use in Architecture and the Built Environment, University of Oum El Bouaghi, Oum El Bouaghi 04000, Algeria
² Laboratory of Bioactive Molecules and Applications (LBMA), Echahid Cheikh Larbi Tebessi University, Tebessa 12002, Algeria
³ Laboratory of Natural Resources and Management of Sensitive Environments, Larbi Ben M’Hidi University, Oum El Bouaghi 04000, Algeria
⁴ Laboratory of Biomolecules and Plant Breeding, Life Sciences and Nature Department, Faculty of Exact Science and Life Sciences and Nature, University of Larbi Ben M’Hidi, Oum El Bouaghi 04000, Algeria
⁵ Physico-Chemical Analysis Technical Platform, El-Hadjeb University Campus, Biskra 07000, Algeria
⁶ Physics Laboratory of Thin Films and Applications (LPCMA), University of Biskra, 07000, Algeria

Abstract: The corrosion inhibition behavior of X60 carbon steel in 1 M hydrochloric acid (HCl) solution by a hydro-methanolic extract of Opuntia ficus-indica L. (prickly pear cactus) was investigated using gravimetric, manganimetric titration, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The extract was prepared by maceration of dried cactus cladode powder in a water/methanol (30:70 v/v) solvent system. The antioxidant activity of the extract was evaluated by the DPPH free radical scavenging assay. Optical microscopy was used to characterize steel surface morphology before and after immersion at various inhibitor concentrations. Results demonstrated that the extract significantly reduced the corrosion rate of X60 steel, with inhibition efficiency increasing with increasing inhibitor concentration. A maximum inhibition efficiency of 87.6% (gravimetry), 81.9% (EIS), and 77.4% (polarization) was recorded at the optimum concentration of 700 ppm. Polarization curves confirmed a mixed-type inhibition mechanism, simultaneously retarding both anodic dissolution and cathodic hydrogen evolution without significantly shifting the corrosion potential. Impedance data showed a systematic increase in charge transfer resistance (R_ct) and decrease in double-layer capacitance (C_dl) with increasing inhibitor concentration, consistent with the formation of a protective adsorbed film. The observed inhibition is attributed to the adsorption of phytochemical constituents–principally polyphenols, flavonoids, tannins, and saponins–onto active surface sites. These findings suggest Opuntia ficus-indica extract as a promising, environmentally friendly green corrosion inhibitor for carbon steel in acidic media, providing moderate, concentration-dependent protection at low cost.

Keywords: Opuntia ficus-indica, X60 steel, green inhibitor, gravimetry, EIS, polarization

Int. J. Corros. Scale Inhib., 2026, 15, no. 3, 502-519
doi: 10.17675/2305-6894-2026-15-3-22

Download PDF (Total downloads: 11)

Back to this issue content: 2026, Vol. 15, Issue 3 (pp. 1-... (in progress))