Protective Effect of CeO₂-Enhanced Epoxy Coatings with Embedded Benzotriazole Corrosion Inhibitor

In order to enhance the long-term protective performance of water-based epoxy coatings，benzotriazole (BTAH) corrosion inhibitor was incorporated into hollow cerium oxide (CeO2) nanocontainers，resulting in the preparation of BTAH＠CeO2-doped epoxy coatings.The surface morphology，chemical composition and corrosion resistance of the epoxy/BTAH＠CeO2 composite coating were characterized using scanning electron microscopy (SEM)，X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS).The results showed that the loading amount of BTAH inhibitor in the CeO2 nanocontainers was 24.7%.The BTAH inhibitor was able to be rapidly released from the CeO2 nanocontainers，with a release amount reaching 92.6%after 8 h.The BTAH＠CeO2 particles were uniformly dispersed in the water-based epoxy resin and effectively filled the microscopic voids inside the coating.Electrochemical impedance testing results after corrosion in a 3.5%NaCl solution for 1 h indicated that the coating resistance of the epoxy/BTAH＠CeO2 composite coating was 16.7 times higher than that of pure epoxy coatings.After immersion in a 3.5%(mass fraction) NaCl solution for 30 d，the polarization resistance loss rate of the epoxy/BTAH＠CeO2 composite coating was only 10.6%compared to 1 h of immersion，demonstrating excellent long-term protective performance.