Massive discharge of oily wastewater and frequent occurrence of offshore oil spills have posed an enormous threat to the socioeconomic and ecological environments. Janus membranes with asymmetric wettability properties have great potential for oil/water separation applications and have attracted widespread attention. However, existing Janus membranes still suffer from complex and costly manufacturing processes, low permeability, and poor recyclability. Herein, a novel and facile strategy was proposed to fabricate a Janus copper mesh with opposite wettability for unidirectional water transport and efficient oil/water separation. The hydrophilic side of the Janus copper mesh was prepared by coating it with Cu(OH)₂ nanoneedles via a chemical oxidation method. The hydrophobic side was fabricated by coating it with hydrophobic SiO₂ nanoparticles via a facile spraying method. The as-prepared Janus copper mesh showed asymmetric surface wettability, which can achieve unidirectional water transport and efficient oil/water separation with excellent recyclability, exhibiting great application potential for droplet manipulation and wastewater purification.

中文翻译：

---

SiO2喷涂制备Janus铜网用于单向输水和油水分离

含油废水的大量排放和海上溢油事件的频繁发生，对社会经济和生态环境造成了巨大威胁。具有不对称润湿特性的Janus膜在油水分离应用中具有巨大的潜力，并引起了广泛的关注。然而，现有的Janus膜仍然存在制造工艺复杂且成本高、渗透性低、可回收性差等问题。在此，提出了一种新颖且简便的策略来制造具有相反润湿性的Janus铜网，以实现单向水传输和有效的油/水分离。 Janus铜网的亲水面是通过化学氧化方法在其上涂覆Cu(OH) ₂纳米针而制备的。疏水侧是通过简单的喷涂方法用疏水性 SiO ₂纳米颗粒涂覆而制成的。所制备的Janus铜网表现出不对称的表面润湿性，可以实现单向水传输和高效的油水分离，并具有优异的可回收性，在液滴操纵和废水净化方面表现出巨大的应用潜力。