Corrosion prevention capability of 1,2,3–triazole derivative on mild steel in an acidic medium: Experimental and theoretical approach

Abstract

The popularity of triazoles for metal corrosion inhibition has increased in recent years. These compounds form a protective film over the metal, which inhibits the interaction among the corrosive agent and metal. By blocking the sites where corrosion typically occurs, triazoles significantly extend the lifespan of metal structures. This makes them an effective and economical choice for various industrial applications. This study explores the ability of 4–nitro–1–octyl–5–phenyl–1H–1,2,3–triazole (NOPT) to inhibit corrosion. The structure of the investigated inhibitor was determined using Proton Nuclear Magnetic Resonance and Carbon–13 Nuclear Magnetic Resonance (¹H NMR and ¹³C NMR) spectroscopy, while its purity was confirmed using Thin Layer Chromatography (TLC). The anticorrosive properties of NOPT on mild steel (MS) samples immersed in 1.0 M HCl were investigated by electrochemical and chemical methods. The inhibitory performance of NOPT was evaluated using scanning electron microscopy (SEM), energy dispersive X–ray spectrometer (EDS) and an atomic force microscope (AFM). The inhibitor reaches its maximum inhibition efficiency of 88.78 % at 150 ppm when the temperature is 302 K. NOPT was found to regulate both cathodic and anodic reactions, and the Langmuir model followed the adsorption isotherm. Based on thermodynamic parameter values, it is suggested that triazoles molecules are physically adsorbed on MS surfaces. Density functional theory (DFT) of NOPT in gas and water phases aligns well with experimental findings. SEM and AFM images indicate that the MS sample immersed in an acidic solution with studied triazole derivative has a smoother surface compared to the acidic solution without the inhibitor. EDS findings confirmed the existence of NOPT molecules on the metal surface.