This study developed active-passive anticorrosion coatings using epoxy resin loaded with CeO2 (cerium oxide), carbon-coated cerium oxide (CeO2@C), and carbon hollow sphere (CHS) particles. Cerium oxide particles were synthesized via a hydrothermal method to achieve a uniform, semispherical morphology and improve dispersion stability. Event tip: Waterborne High Performance CoatingsEC Short Course “Waterborne High Performance Coatings” taking place on March 18, 2025, will dive into the rapidly developing field of waterborne coatings. Synergistic protective effect of the nanocompositesThe study showed that the combination of CeO2, CeO2@C, and CHS particles significantly enhanced the corrosion protection. After 40 days in a 3.5% NaCl solution, the impedance value of the coating increased substantially, indicating excellent corrosion resistance.