Engineered Janus cellulose membrane with the asymmetric-pore structure for the superhigh-water flux desalination

Membranes are the dominant material for seawater desalination and clean-water harvesting, which are commonly composed of synthetic polymers, showing low hydrophilicity and environmental hazard. Herein, we developed a low-cost, intrinsically green, superhigh-water flux Janus cellulose membrane (CEM) via a facile cellulase etching strategy. Coating cellulase on the single surface of cellulose membrane (such as top surface), triggers effective etching on its top section rather than bottom section, which architects an asymmetric-pore structure of the Janus CEM including porous top-and dense bottom-layer. Such distinction endows the Janus CEM with an unprecedented high-water flux of 135.75 LMH and a low salt-water ratio of 0.29 g·L-1 for 1 M NaCl solution, which is 17-time higher and 62-time lower than that of the pristine CEM. Our Janus CEM enables a promising participant for the advanced membrane materials toward versatile separation engineering.