Patterned Nanobrush Nature Mimics with Unprecedented Water‐Harvesting Efficiency

Abstract

AbstractWater scarcity is one of the most alarming problems of the planet. An ambient ion based method is developed to make hydrophilic‐hydrophobic patterned silver nanowires (NWs) as humidity harvesters of unprecedented efficiency. Such water harvesters are developed by two‐step surface modification of the as‐synthesized NWs (known from a report earlier) using electrospray. These patterned NWs of ≈20 µm length and ≈200 nm width grown over a relatively large area (2 × 2 cm2) exhibit atmospheric water capture (AWC) efficiency of 56.6 L m−2 d−1, the highest reported so far. The whole fabrication process of the surface is performed under ambient conditions with a home‐built nanoelectrospray ion source, without the help of any sophisticated instrumentation. The synthesized material combines and mimics two exciting examples of AWC in nature, which are cactae and Namib Desert beetles, which utilize AWC for their living. It is believed that the combination of the special features of the above two natural species helps to achieve the highest water capture efficiency reported till date. A working prototype using this surface for AWC is also fabricated.