Facilely fabricating large-area robust heterogeneous wettability surface by mask-patterned ultrafine anode scanning electrodeposition for efficient water collection

Water collection has been highly demanded in water-deficient areas, and heterogeneous wettability surfaces have been proven to be significantly advantageous in meeting this demand. However, the currently available large-area metallic surfaces fabricated are less efficient, cost-effective, and mechanically robust. To overcome these shortages, a unique mask-patterned ultrafine anode scanning electrodeposition (MUAS-ECD) technology was proposed in this work, and simultaneously a nonconventional deposit design and preparation process strategy was developed. With the MUAS-ECD, a functional heterogeneous wettability surface containing a number of parallel superhydrophilic convex strips and hydrophilic concave grooves can be constructed concurrently on a large-area metallic substrate. With the design and preparation strategy, the robust convex nickel strips with alternately stacked compact and coarse material structural layers could be facilely formed only by adjusting the processing voltage. It was found that the achieved 5-layer deposit patterned strip-groove structural surfaces (5-LDPS) demonstrate an incredibly high water collection rate of 1.61 g h(-1)cm(-2). Surprisingly, these surfaces still exhibit excellent water-collection ability even after 100 abrasion cycles with sandpaper. The proposed MUAS-ECD and accompanying process strategy show great potential in structuring large-area robust heterogeneous wettability metallic surfaces for efficient fog harvesting in water-starved environments.