Rahul Mishra, Shailendra Yadav, Vinay Pathak and Chitrasen Gupta
Abstract
Corrosion of mild steel in acidic environments is a significant challenge in industrial applications, necessitating the search for effective and environmentally friendly inhibitors. This study investigates the potential of expired itraconazole as a green corrosion inhibitor for mild steel in 1N H2SO4 using weight loss, potentiostatic polarization, and scanning electron microscopy (SEM) techniques. The weight loss studies demonstrated that inhibition efficiency increased with inhibitor concentration, achieving a maximum of 88.81% at 500 ppm and 45°C. However, a slight decrease in efficiency was observed at higher temperatures. Potentiostatic polarization studies confirmed the mixed-type inhibition behavior, with a significant reduction in corrosion current density (Icorr), achieving an inhibition efficiency of 87.34% at 500 ppm. SEM analysis further supported these findings, revealing a protective surface layer formed by the inhibitor, reducing surface deterioration. The results confirm that expired itraconazole is an effective, sustainable, and cost efficient corrosion inhibitor, offering an alternative use for pharmaceutical waste in industrial applications.