Evaluation of corrosion inhibition effect of hybrid organic Ziziphus spina-christi leaf extract and zinc sulfate corrosion inhibitor on mild steel in saline solutions

This study's objectives were to investigate the inhibitory and adsorption qualities of aqueous extracts of Ziziphus spina-christi (ZSC) leaves and ZnSO4 and to create a new generation of corrosion-inhibiting pigments based on zinc sulfate-ZSC leaf extract (ZSC/ZnSO4) for the corrosion of mild steel in 3.5 weight percent NaCl solution.

In this study, the ZSC extract was introduced to a ZnSO4 suspension and swirled using a magnetic stirrer for 48 hours at 25 °C until the functional groups of the ZSC and ZnSO4 interacted and a hybrid pigment was produced. Scanner electron microscopy (SEM) and thermal gravimetric analysis (TGA) techniques were used to analyze the morphology and chemistry of the produced pigments. Then, using polarization tests, electrochemical impedance spectroscopy (EIS), and FE-SEM/EDS analyses, the inhibitory impact of pigments in preventing corrosion of carbon steel in 3.5 weight percent NaCl solutions was assessed.

Results showed that the lone pair electrons of heteroatoms present in the structure of the chemical compounds of ZSC extract were successfully shared with vacant orbitals of Zn2+ cations to create the hybrid ZSC/ZnSO4 pigment.

Results :

from electrochemical experiments indicated that the ZSC/ZnSO4 hybrid pigment could significantly slow down the corrosion of the steel sample. Both the anodic and cathodic processes were noticeably repressed and inhibited in the presence of ZSC/ZnSO4 extract due to the synergistic impact between ZSC and Zn2+ cations.