Investigating the effectiveness of Watermelon extract-zinc ions for steel alloy corrosion mitigation in sodium chloride solution

Abstract In the present study, the green-renewable Watermelon extract (WME):Zn inhibitive complexes were introduced in order to reduce the mild steel (MS) corrosion in a 3.5% sodium chloride (NaCl) solution. The chemistry of WME:Zn compounds were probed via the Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible (UV–Vis) spectroscopies and the results displayed successful interactions between the WME and Zn. The WME:Zn complex anti-corrosion impact and protection mechanism were discovered by EIS and Tafel analyses during 72 h exposure to the neutral chloride-type solution, respectively. The test results confirmed that the WME:Zn controlled 96% of MS corrosion in the saline solution with the help of mixed-type interactions. The immersed samples were examined by field-emission scanning electron microscope (FE-SEM) (equipped with energy dispersive spectroscopy (EDS)) and the structures of the deposited oxides were assessed by grazing incidence X-ray diffraction (GIXRD) techniques, that confirmed the WME:Zn protective layer generation over the MS substrate. The atomic force microscope (AFM) displayed the generation of the high smooth layer with lower heterogeneities and the contact angle (CA) results proved the semi-hydrophilic behavior of the inhibited samples.