Underwater superoleophobic copper mesh coated with block nano protrusion hierarchical structure for efficient oil/water separation

Abstract

Compared with monolayer nanosheet membranes, multilayer nanosheet membranes have low energy consumption and can be mass-produced for industrial applications. Herein, a multi-layer nanostructured membrane, nickel-doped brochantite/Cu(OH)2 nano protrusion structure coated copper meshes (NBCPCMs), were successfully prepared. Firstly, the surface of the copper mesh was etched by chemical oxidation to form a disordered copper hydroxide nanosheet layer. Secondly, the etched copper mesh surface was coated with nickel-controlled brochantite block-like protrusions by hydrothermal synthesis method, and nickel-doped brochantite/Cu(OH)2 nanosheets were generated by high pressure. The results showed that NBCPCM-4 had excellent hydrophilic/underwater superoleophobicity, the oil–water separation efficiency of immiscible cyclohexane/water mixture was the highest, about 98.54%, and still had a very high flux (>60 (kL/(h·m2))) after multiple cycles of separation. In addition to ultra-high separation efficiency, NBCPCM-4 also had super durability. The copper mesh maintained good underwater superoleophobicity in different aqueous solutions. Therefore, NBCPCM-4 is a potential high-efficiency and sustainable oil–water separation membrane material. It is expected that the developed technology is useful for sea transportation and marine environment management, along with other industries.