Application of expired Febuxostat drug as an effective corrosion inhibitor for steel in acidic medium: Experimental and theoretical studies

This work investigates the possibility of using expired Febuxostat, a drug mainly used to treat gout, as a corrosion inhibitor for steel in solutions containing Hydrochloric acid (HCl), which is an unusual but potentially successful approach. The goal of this research is to recycle pharmaceutical waste for useful purposes while also meeting the requirement for sustainable and economical corrosion mitigation techniques. The study includes various analytical techniques, like SEM, weight loss, electrochemical techniques, and density functional theory (DFT) to evaluate the efficacy of expired febuxostat as a corrosion inhibitor for steel in 0.5 M HCl solution. The EIS and PDP curve results showed a direct correlation between the concentration of Febuxostat and the inhibition efficiency. The active center of the electrode surface is blocked by the drug molecules, which reduces the corrosion mechanism. The data from the Langmuir adsorption isotherm validates a physiochemical process. Moreover, SEM investigations show that steel has a smoother surface. The adsorption behavior of Febuxostat molecules on the steel surface is investigated, providing insight into the chemical mechanisms underlying the inhibitory effect.