Surface analysis and interface properties of 2-aminobenzimidazole corrosion inhibitor for brass in chloride solution

This work presents a corrosion study of 2-aminobenzimidazole (ABI) as a corrosion inhibitor for brass in chloride solution. Electrochemical, field emission scanning electron microscopy, atomic force microscopy, and contact angle measurements showed that ABI mitigates brass corrosion after short-, medium-, and long-term immersion periods. Next, a detailed surface analysis of the ABI adsorbed on the brass surface was performed using attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) techniques. XPS imaging was performed in association with principal component analysis to determine the different phases on the surface. In order to describe the in-depth composition of the ABI surface, an angle-resolved XPS analysis was performed. This analysis was further supported by gas cluster ion beam sputtering to gradually remove the ABI surface layer, and XPS analysis was performed after each sputtering cycle. Finally, TOF-SIMS analyses showed the formation of Cu/Cu₂-ABI and Zn-ABI compounds, the 2D distribution of ABI-related compounds, and their thermal stability on the brass surface. Graphical abstract.