One-step constructed LDH/ZIF-8 coating on AAO with stearic acid modification for synergistic anti-icing and corrosion protection

This study presents a facile one-pot hydrothermal strategy for the in-situ growth of a layered double hydroxide and ZIF-8 composite coating on anodic aluminum oxide. The synthesis temperature was optimized within the range of 110–130 °C, which enables the synchronous formation of a uniform and well-interlocked LDH/ZIF-8 microstructure. Subsequent modification with stearic acid (SA) effectively imparts hydrophobicity to the coating, yielding a water contact angle of 136.4 ± 0.10°. The obtained LDH/ZIF-8@SA coating exhibits remarkable anti-icing performance, delaying ice nucleation and complete freezing of a water droplet at -15 °C by 93% and 45%, respectively, compared to the bare AAO substrate. Electrochemical tests demonstrate excellent corrosion resistance, with the SA-modified coating showing a corrosion current density of 1.413  ×  10 -9  A·cm -2 after 3 days of immersion, and a charge-transfer resistance up to 1.362  ×  10 8  Ω·cm 2 after 14 days of immersion in 3.5 wt.% NaCl solution. Moreover, the coating possesses a low friction coefficient of 0.318 ± 0.045. Density functional theory calculations were performed to elucidate the interfacial bonding mechanism among ZIF-8, SA and LDH.