Ni-Al layered double hydroxides (LDHs) coated superhydrophobic mesh with flower-like hierarchical structure for oil/water separation

Recently, there is an urgent demand to remove oil and organic solvents with low surface tension from oily wastewater, which promotes the application of interface biomimetic materials in oil/water separation. In our work, a novel Ni-Al LDHs coated superhydrophobic and superoleophilic stainless steel mesh (SS-SSM) with efficient oil/water separation performance was successfully prepared. The 3D flower-like structure intercalated by LDHs monocrystalline flakes was anchored on metallic wires in urea solution by a hydrothermal method and decorated with low surface energy molecules. The as-prepared mesh exhibited perfect superhydrophobicity with water contact angle of 156 degrees and sliding angle of 5 degrees, thus achieving self-cleaning property. In addition, the separation efficiency for a series of oil/water mixtures of the coated mesh was studied, which was up to 98% for most sample oils. More importantly, even treated under severer conditions such as ultrasonic, abrasion and chemical etching solution, the as-prepared meshes possessed good reproducibility in terms of contact angles and separation efficiencies. It is expected that the designed mesh could provide a b brand-new method for super-hydrophobic surface coating, making it a potential functional material for self-cleaning, anti-corrosion, fluid drag reduction and oil/water separation.