Phytochemically Aided Synthesis of MgO Nanoparticles Utilizing Orange Peel Extract for Inhibition of SS Grade 202 against Corrosion in HCl Environment

Among iron-based alloys, stainless steel (SS) is known for its substantial corrosion resistance under mild conditions. The major alloy element, Cr, contributes to the corrosion resistance of SS, which is categorized into several Grades depending on the Cr composition. Grade 202 has become a major concern at industrial scale due to several factors whilst the concern on corrosion monitoring and its inhibition have not been considered in a sustainable approach. Although various nanoparticles (NPs) have been implemented as corrosion inhibitors due to their high adsorption capacity on metal surfaces forming a passive film, low-cost MgO-based substances against corrosion of SS Grade 202 has not been attempted. In this study, MgO NPs derived with the aid of orange peels are found to exhibit corrosion inhibition ability through the formation of oxide passive film. Large surface area, durability and sustainably of synthesized MgO NPs pursue prominent corrosion inhibition efficiency toward SS Grade 202 regardless of the exposure of extreme environments according to a multi-technique approach of mass loss, potentiodynamic and electrochemical impedance spectroscopic investigation performed under different experimental conditions. 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 M and 0.50 M HCl, superior corrosion inhibitory action can be achieved with the aid of phytochemically synthesized 0.10 M MgO NPs which illustrates inhibition efficiency of 96.6% and 91.9%, respectively.