Multi-bioinspired hierarchical Janus membrane for fog harvesting and solar-driven seawater desalination

Abstract

Harvesting water from fog as well as the ocean provides an efficient and sustainable solution for producing clean drinking water. Till now, many different water harvesting materials have been widely reported, however these materials are often only applicable to a single scenario. Inspired by nature, here a novel hierarchical multi-biomimetic membrane is introduced. The mesh-like membrane is composed of polyurethane nanofibers with hydrophilic carbon nanospheres and carbon nanotubes anchored on the surface. It can not only be used to collect fog in the fog flow, but also can be used for photothermal evaporation under the driving of sunlight to collect water. The water harvesting efficiency of this membrane can reach 1666.2 mg cm−2 h−1, the evaporation rate of natural seawater can reach 1.05 kg m−2 h−1 under 1 sun, moreover it is reusable to realize long lasting efficient water harvesting. At present, there are few reports about the structural characteristics of biomimetic termites and fungi and the combination of carbon nanomaterials and polymer nanofibers for the construction of multi macro-micro-nanostructures for water harvesting. Therefore, this research can broaden the way of making biomimetic water harvesting materials in the future and provide new inspiration for the sustainable production of clean water.