Enhancing copper corrosion resistance in highly caustic environments: Evaluation of environmentally friendly inorganic inhibitors and mechanistic insights

During this study, two inorganic glasses materials with chemical compositions of (1−x) (2Bi₂ O₃ ⋅B₂ O₃)–x BaO (with x=0.2 (BiB-Ba_0.2) and x=0.6 and (BiB-Ba_0.6)) were synthetized characterized and investigated as viable, ecofriendly, and sustainable inhibitors to mitigate copper corrosion in a highly caustic solution containing 0.5 M H₂SO₄ solution. To evaluate inhibition processes, several techniques were employed, including potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). Furthermore, the results show that the two inhibitors studied, BiB-Ba_0.2 and BiB-Ba_0.6, have higher corrosion inhibition efficiencies at the optimum concentration (10⁻³ M), reaching 91.2 % and 90.8 %, respectively. Moreover, these findings suggest that the two inorganic compounds elaborated possess inhibitors of mixed types. Copper oxide (Cu₂O) production is markedly delayed when the two inhibitors are added to the acid medium, according to the findings of the XRD, FTIR, SEM/EDS, and AFM investigations. This outcome is explained by the development of a shield that lessens surface damage to copper metal, producing a smoother surface morphology.