Bionic multifunctional copper mesh for self-cleaning, oil/water separation and fog collection

Abstract

With the recovery of crude oil leakage becoming an integral part of the carbon neutrality strategy and the increasing scarcity of global freshwater resources, achieving efficient treatment of oil-water mixtures and sustainable access to water resources is a pressing scientific challenge that needs to be addressed urgently. Therefore, this study combines wire electrical discharge machining (WEDM) technology with an in-situ growth strategy to construct a multifunctional superhydrophobic bionic copper mesh (MS-BS) inspired by the superhydrophobic and self-cleaning properties of gecko skin. This design exhibits outstanding comprehensive performances in terms of self-cleaning, mechanical and chemical stability, corrosion resistance, oil-water separation ability, and fog collection efficiency. The MS-BS demonstrates good antifouling and self-cleaning capacity with a water contact angle (CA) of 161.5° and a rolling angle (RA) of 0.1°. After 200 abrasion cycles (1.63 KPa), the MS-BS remains hydrophobic (CA = 140°) and shows good resistance to different pH solutions, confirming superior mechanical and chemical stability. In addition, the MS-BS is applied for highly efficient oil-water mixture separation, achieving a maximum separation efficiency of about 98.5 % and the highest separation flux of 160,000 L·m⁻²·h⁻¹, and even after 50 operation cycles, it maintains 96 % separation efficiency. In addition, the MS-BS provides a potential fog collection strategy, showing a fog collection efficiency of 3386 mg·cm⁻²·h⁻¹, which is 12.7 times greater than that of the ordinary copper sheet. This bionic integrated surface design strategy presents a new research path for developing high-performance environmental governance materials and holds broad application prospects.