Evaluation of <i>Boerhaavia diffusa</i> roots extract as a sustainable corrosion inhibitor for mild steel in sulfuric acid environments

Abstract Mild steel (MS) is a widely used type of steel because of its different types of qualities like versatility, affordability, and ease of modification. On the other hand, its vulnerability to corrosion may somewhat detract from its merits. To mitigate the corrosion impacts various techniques are applied. The use of corrosion inhibitors remains one of the most effective strategies to prevent corrosion, especially in environments where sustainability is increasingly important. In this study, we evaluated the corrosion‐inhibiting properties of Boerhaavia diffusa (BHD) root extract in various concentrations (1–6%) on mild steel (MS) in an acidic solution (0.1 M H 2 SO 4 ). To characterize the functional groups present in the BHD extract, Fourier‐transform infrared spectroscopy (FTIR) was employed. A combination of methods, including weight loss measurements, electrochemical polarization, electrochemical impedance spectroscopy (EIS), metallurgical research microscopy (MRM), and scanning electron microscopy (SEM), were used to assess the effectiveness of corrosion inhibition. BHD extract showed a maximum corrosion inhibition efficiency (IE) of 86.58% and the maximum charge transfer resistance ( R ct ) of 308 Ω cm 2 was recorded for 6% concentration at 25 °C. This research study was carried out at 25, 35 and 45 °C. The study revealed that BHD is an excellent green corrosion inhibitor.