Contribution to the corrosion inhibition of aluminum by aqueous extract of Moringa oleifera in 2 M HCl

The anti-corrosion properties of Moringa oleifera extract (MOE) have been extensively studied for Al in two molar HCl solution using a variety of techniques, including atomic force microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, and weight loss analysis. According to the study, the inhibitory efficiency (% IE) increases with extract dose but decreases with temperature rise from 25 to 40 °C. The highest 90.1 percent inhibitory efficiency was achieved at 25 °C extract dosage of 300 ppm. MOE functions as a mixed-type inhibitor, affecting both anodic and cathodic processes, according to PDP research. The double layer capacitance (Ceff) declines from 214 to 56 µFcm−2 and the charge transfer resistance (Rct) increases from 3.1 to 27.2 sΩ cm2 with increasing MOE dose, as demonstrated by the Nyquist plot. The Langmuir adsorption isotherm is followed by MOE's adsorption on Al surfaces. The AFM and FTIR measurements corroborate MOE's adsorption on the Al surface. Based on the findings, it can be said that MOE can be utilized as a green inhibitor to reduce metal corrosion in harsh environments.