Green metal protection: Potency of ethanolic extracts of Lagenaria breviflora leaf as inhibitor for mild steel dissolution in 0.5M HCl medium

• The study established the effectiveness Lagenaria breviflora leaf extract as corrosion inhibitor for mild steel in HCl • The inhibitor is a cost-efficient and eco-friendly corrosion inhibitor that can serve as a potential alternative to the conventional corrosion inhibitors. The increase in toxic substances in the environment has become a global concern. Thus, the need for eco-friendly green alternatives in corrosion inhibitor formulation and its optimization for improved performance informed the present study. The leaf extract Lagenaria Breviflora (LELB) was keenly selected and optimized to the most effective dosage as a corrosion inhibitor for mild steel (MS) in a 0.5M HCl corrosive environment. Phytochemical analysis, FTIR, thermodynamic, Kinetic, weight loss, and electrochemical studies were utilized to assess the active functionalities for the corrosion inhibition potential of the new material. The phytochemical analyses revealed the presence of flavonoids, phenols and tannins. FTIR displayed functionalities such as O-H and C-O, as responsible for anchoring LELB molecules to the metal surface. As a result, the molecules got adsorbed to the metal via a chemical adsorption mechanism, best supported by the Langmuir adsorption isotherm. The order of reaction showed that the rate constant (K) is directly proportional to LELB inhibitor concentrations, giving the coefficient of correlation R 2 approximately unity. This resulted in a protection efficiency of 87.0 % in the presence of LELB inhibitor by the electrochemical method.