ZIF-67 metal-organic framework decorated g-C3N4 nanosheets with inbuilt organic-inorganic corrosion inhibitor for self-healing epoxy anti-corrosion coating

This study presents the development and evaluation of a novel anti-corrosion coating based on ZIF-67 metal-organic framework decorated g-C3N4 nanosheets with inbuilt benzotriazole (BTA) and cerium (Ce3+) corrosion inhibitors. The primary focus was on the synthesis of Ce-BTA@ZI@GN nanopigments and their integration into epoxy coatings to enhance the corrosion resistance of mild steel (MS) in marine environments. Comprehensive characterization techniques, including FTIR, XRD, XPS, BET, and UV–Vis analyses, confirmed the successful development of the nanopigments and their homogeneous dispersion within the epoxy matrix. The corrosion mitigation performance was assessed using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and salt spray tests. According to the PDP findings, the corrosion rate (CR) of MS immersed in a solution containing the released BTA and Ce3+ inhibitors decreased by 50 % compared to a blank solution. EIS results indicated that the inclusion of BTA and Ce3+ inhibitors resulted in a nearly 5-fold improvement in total resistance compared to the blank/EP coating. Furthermore, salt spray tests conducted over 20 days demonstrated the exceptional anti-corrosion properties of the BTA@ZI@GN and Ce-BTA@ZI@GN nanopigments, highlighting their potential for long-term protection against corrosion in harsh marine conditions. These findings suggest that the developed coatings not only provide effective corrosion resistance but also offer self-healing properties, making them suitable for advanced protective applications in marine engineering.