Easily scaled-up and portable 3D polysulfone hollow fiber membrane tree for high-efficient solar-driven clean water production

Abstract

Solar-driven water evaporation based on photothermal conversion materials, such as woods, sponges, and membranes, have been proved to be promising in the field of fresh water generation. It's urgent to develop portable, versatile, and efficient photothermal materials for affordable freshwater supply. Here, a hydrophilic polysulfone hollow fiber membrane (PSF HFM) with gradient porous structure and diameter of 50 μm was prepared through one-step phase inversion method. Inspired by nature, a highly efficient 3D solar-driven steam evaporator was fabricated via chemical vapor deposition polymerization (CVDP) of hydrophobic polypyrrole (PPy) on PSF HFMs. With rational 3D structure, capillary-driven water transportation property, optical absorption as high as 95%, heat localization, photothermal conversion, a solar-driven water evaporation rate of 2.6 kg m−2·h−1, and the conversion efficiency of 173.2% could be achieved. Furthermore, the HFM tree with affluent light-harvesting, efficient thermal management, and excellent stability showed a purified water collection efficiency of 14.18 L/(m2·day) in practical application, providing a latent way to boost water purification, regeneration, and desalination.