A Green and Sustainable Approach for Corrosion Inhibition of Carbon Steel in HCl Solution by Abelmoschus Esculentus Peduncle Extract

The corrosion of carbon steel in hydrochloric acid (HCl) is a major economic and safety problem in industrial processes such as pickling and descaling. This research investigates the use of peduncle extract from Abelmoschus esculentus (okra) as a green, ecological corrosion inhibitor. A structured literature review indicates that okra extracts, particularly mucilage, can achieve high inhibition efficiencies (up to 96%) by adsorbing onto carbon steel surfaces, predominantly following the Langmuir adsorption isotherm. Experimentally, weight loss measurements were performed on carbon steel in 1 M HCl with varying concentrations of okra peduncle extract (1–3) g at 20–60 °C. Results showed high inhibition efficiency (up to 98.4% at 40 °C for 3 g extract), which was concentration-dependent and exhibited a slight decrease at 60°C (90.7%). Thermodynamic analysis indicated a spontaneous physisorption process. The synthesized evidence confirms that Abelmoschus esculentus peduncle extract is a potent, sustainable, and economically viable alternative to traditional synthetic corrosion inhibitors.