Two-dimensional ZnO nanoflakes coated mesh for the separation of water and oil

Through the low-temperature hydrothermal route, one kind of two-dimensional (2D) ZnO nanoflakes was grown on the stainless steel mesh coated by Al. After being modified by stearic acid (SA), the coated mesh was found to be superhydrophobic and superoleophilic simultaneously, and the water contact angle can reach to 156.3 ± 2.1°. It could separate a variety of water and oil mixture. The separation efficiency was up to 95%. It was found that the oil with larger surface tension can be easier to penetrate the coated mesh, and then the separate efficiency increased. Besides, a detailed investigation showed that the special hierarchical micro/nanostructures and appropriate size of the mesh played an important role in obtaining the superhydrophobicity and superoleophilicity. The coated mesh might be practically employed in oil pollution.