SiO2 shell on ZnO nanoflake arrays for UV-durable superhydrophobicity on Al substrate

ZnO nanoflaker arrays were fabricated on Al substrates by hydrothermal route at the temperature of 90 °C. Then the arrays were coated with SiO₂ film by pulsed laser deposition (PLD) process with different deposition time, and finally hydrophobized with hexadecyltrimethoxysilane (HDTM). It is found that the SiO₂ film have little effect on the superhydrophobic property of ZnO nanoflaker arrays. However, it has greatly improved the UV-durability of the superhydrophobicity of ZnO nanoflaker arrays. The water contact angles were almost unchanged even after UV exposure for 40 h when the deposition time is about 10 min. Thus, the SiO₂/ZnO/Al structure his paper may provide an effective and simple to design UV-durable superhydrophobic surface.