posted on 2024-01-04, 13:03authored byDian Gong, Binghai Wen, Lu Wang, Hongxuan Zhang, Huiling Chen, Jingrui Fan, Zhi Li, Long Guo, Guosheng Shi, Zhigao Zhu, Xing Liu, Gaofeng Zeng
Billions
of populations are suffering from the supply–demand
imbalance of clean water, resulting in a global sustainability crisis.
Membrane desalination is a promising method to produce fresh water
from saline waters. However, conventional membranes often encounter
challenges related to low water permeation, negatively impacting energy
efficiency and water productivity. Herein, we achieve ultrafast desalination
over the newly developed alkadiyne–pyrene conjugated frameworks
membrane supported on a porous copper hollow fiber. With membrane
distillation, the membrane exhibits nearly complete NaCl rejection
(>99.9%) and ultrahigh fluxes (∼500 L m–2 h–1) from the seawater salinity-level NaCl solutions,
which surpass the commercial polymeric membranes with at least 1 order
of magnitude higher permeability. Experimental and theoretical investigations
suggest that the large aspect ratio of membrane pores and the high
evaporation area contribute to the high flux, and the graphene-like
hydrophobic surface of conjugated frameworks exhibits complete salt
exclusion. The simulations also confirm that the intraplanar pores
of frameworks are impermeable for water and ions.