Corrosion inhibition properties of Ziziphus spina-christi leaves extract and zinc cations on mild steel in sodium chloride solution

Abstract

In this study, the impact of various quantities of the inorganic inhibitor Zinc Sulfate (ZnSO4) and the extract of the green inhibitor of Ziziphus spina-christi leaf (ZiZi) on the effectiveness of corrosion protection of steel samples were evaluated in 3.5 wt % NaCl via electrochemistry methods and surface characterization. The interactions of the ZiZi components with zinc cations were investigated using Fourier transform infrared spectroscopy (FT-IR) and ultra-violate visible (UV–Vis) analyses. Visual inspections, open circuit potential (OCP) measurements, polarization, electrochemical impedance spectroscopy (EIS) experiments, scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), and grazing incidence X-ray diffraction (GXRD) analyses were used to investigate the inhibitory impact of ZiZi and ZnSO4 in protection against corrosion of metal samples. The electrochemical study findings collected proved that adding zinc ions to ZiZi extract prevented corrosion of steel samples. According to the results of the polarization test, the solution containing 600 ppm ZiZi +200 ppm ZnSO4 had the highest anti-corrosive power of 91.52%. SEM/EDS and GXRD analysis findings verified the successful formation of the Fe+2-Zn+2-ZiZi compounds on the metal surface.