ZnO@ZIF-8 core-shell structure nanorods superhydrophobic coating on magnesium alloy with corrosion resistance and self-cleaning

A longstanding quest in material science has been the development of superhydrophobic coating based on a single material, without the requirement of fluorination or silane treatment. In this work, the micro-arc oxidation (MAO) coating as transition layer can effectively enhance the bonding force of the superhydrophobic coating. The semiconductor@metal organic frameworks (MOFs) core-shell structure was synthesized by a simple self-templating method, and obtained ZnO@2-methylimidazole zinc salt (ZIF-8) nanorods array on magnesium (Mg) alloy. ZnO nanorods not only act as the template but also provide Zn 2+ for ZIF-8. In addition, we proved that the ligand concentration, synthesis time and temperature are the keys to the preparation of ZnO@ZIF-8 nanorods. As we expect, the ZnO@ZIF-8 nanorods array can trap air in the gaps to form an air layer, and the coating exhibits superhydrophobic properties (154.81°). Excitingly, ZnO@ZIF-8 nanorods array shown a superhydrophobic property, without the requirement of fluorination or silane treatment. The results shown that the coating has good chemical stability and self-cleaning performance. Meanwhile, the corrosion resistance has been significantly improved, R ct was increased from 1.044×10 3 to 1.414×10 6 Ω/cm 2 and I corr was reduced from 4.275×10 −5 to 5.611×10 −9 A/cm 2 . Therefore, the semiconductor@MOFs core-shell structure has broad application prospects in anti-corrosion.