Biomimetic Hierarchical TiO2@CuO Nanowire Arrays-Coated Copper Meshes with Superwetting and Self-Cleaning Properties for Efficient Oil/Water Separation

Creating a practical and energy-efficient method with high efficiency to separate oil water mixtures and emulsions is essential for sustainable aquatic ecosystem and waste oil recycling. Herein, we reported a completely inorganic hierarchical TiO2@CuO nanowire array-coated copper mesh membrane fabricated using chemical oxidation and hydrothermal recrystallization. The biomimetic hierarchical nano/micro-structure can form a lotus-leaf-like interface with fine surface roughness and hydration ability, thus endows the membrane superhydrophilic and underwater superoleophobic nature. Thus, the as-synthesized TiO2@CuO nanowire array-coated copper mesh membrane demonstrates promising water flux of 87.6 kL h(-1) m(-1) and ultrahigh separation efficiency with oil residue of only 12.4 mg L-1 in the permeate. Moreover, the uniformly immobilized TiO2 nanoparticles exhibit UV-irradiated photocatalytic ability, which can be effectively regenerate the contaminated membrane after exposure to UV irradiations for 60 min. Therefore, this highly-efficient, reusable, and easy-scalable membrane fabrication strategy may possess practical potential for next-generation oil/water separation application.