Preparation of lotus-like hierarchical microstructures on zinc substrate and study of its wettability

In this paper, we innovatively propose a facile and controllable way to prepare a superhydrophobic Zn/ZnO film on a zinc substrate. In this approach, we soak the acid etched Zn substrate in pure warm water, resulting in the formation of a hierarchical configuration with micron-sized grooves and nanorods. The lotus-like hierarchical Zn/ZnO micro/nano structure can be acquired and tailored under a wide range of reaction conditions by controlling the reaction temperature and duration. The formation mechanism of the hierarchical structure has been discussed. The wettability of as-modified surfaces has been studied through three aspects: superhydrophobicity, oleophobicity (for oily liquids), and oil-water separation properties. What's more, the as-prepared superhydrophobic samples show good thermal stability (under 200 degrees C) and recoverability. This approach offers potential for industrial application of self-cleaning surfaces because of its features such as time-saving, low cost, easy preparation and so on.