Effect of cerium nitrate concentration on corrosion protection of hybrid organic/inorganic Si/Zr sol-gel coating applied on hot-dip galvanized steel

This present work investigates the corrosion performance of hybrid organic/inorganic Si/Zr sol-gel doped with various cerium nitrate concentrations applied on hot-dip galvanized steel. The Si/Zr sol-gel solution was prepared from tetraethyl orthosilicate (TEOS), 3-(trimethoxysilyl)propyl methacrylate (MAPTMS), and zirconium (IV) propoxide (ZTP). The effect of the addition of cerium nitrate was evaluated by electrochemical impedance spectroscopy (EIS) versus immersion in 0.1 M NaCl solution and salt spray test. The results indicated that cerium nitrate contents affected the protective behavior of sol-gel coating in long term. Additionally, the sol-gel doped with 650 ppm Ce (III) presented the optimal corrosion protection of the sol-gel coating formed on hot-dip galvanized steel substrate.