Phytochemically-aided synthesis of MgO nanoparticles facilitated by orange peel extract for corrosion inhibition of stainless-steel Grade 202 in acidic media

Stainless steel (SS) corrosion resistance is mainly attributed to the passivation film created by chromium; nevertheless, corrosion inhibition for SS Grade 202, despite its extensive industrial application, does not manifest any sustainable inhibition strategy. It has been widely acknowledged that nanoparticles (NPs) can adsorb onto surfaces through effective passivation; however, affordable MgO-based inhibitors for corrosion resistance for SS Grade 202 remain untapped territory. This paper presents the synthesis of MgO nanostructured inhibitors using orange peel extract for enhanced corrosion resistance, particularly for highly acidic conditions. Large surface area, durability and sustainably of synthesized MgO NPs pursue prominent corrosion inhibition efficiency toward SS Grade 202 regardless of the exposure to extreme environments via a multi-technique approach. Mass loss measurements are indicative of the impact of chloride environments promoting corrosion, which becomes stronger at lower pH created by HCl acid solutions. Corrosion inhibitory system developed by MgO NPs with the aid of OPE has been able to overcome the corrosive nature of acidic chloride environments as evidenced by much decreased mass loss and much improved polarization resistance values in electrochemical impedance spectroscopy. Linear polarization investigation provides further evidence of having shift of the corrosion potential toward more positive direction and much decreased corrosion rate values in the presence of the corrosion inhibitory system developed. Open circuit potential values are also shifted toward positive direction in the inhibitory system demonstrating less susceptibility to corrosion. Effective synthesis of MgO NPs is supported by XRD peaks at 36.9º, 42.9º, and 62.3º alongside with characteristic FTIR spectral bands. In the presence of 0.25 mol L−1 and 0.50 mol L−1 HCl, superior corrosion inhibitory action can be achieved with the aid of phytochemically synthesized 0.10 mol L−1 MgO NPs illustrating inhibition efficiency of 96.6% and 91.9%, respectively.