Tubular metal–organic framework membranes enabling exceptional atmospheric water harvesting by fast air permeation

Abstract

Atmospheric water harvesting (AWH) with monolithic metal–organic frameworks (MOFs) represents an industrially favorable solution to freshwater scarcity, while its water productivity is rather poor due to the limited water adsorption–desorption cycling capacity of MOFs. Herein, versatile tubular MOF membranes (TMMs) with well-aligned lamellar microstructures and containing helical porous carbon strips (PCSs) are presented. Such unique shapes and microstructures of TMMs allow the airflow to rapidly pass through TMM walls, resulting in their highly efficient surface exposure to air and dramatically accelerated atmospheric water adsorption. PCSs embedded within TMMs enable to deliver localized electrical heating (LEH) to achieve rapid and sufficient heating of the entire TMMs, endowing TMMs with highly efficient water desorption capacity. These merits synergistically impart TMMs with fast and well-controlled water adsorption–desorption cycling capabilities, enabling the TMM-based AWH devices to deliver 6.2, 3.2 and 8.6 LH2O kgTMM-1 day−1 of record-high water productivity at 20 %, 35 % and 60 % relative humidity and 25 °C, respectively. The TMM with fast air permeation and sufficient LEH capacity thus demonstrate a novel design of industry-favorable AWH sorbent towards exceptional water productivity, paving a bright avenue towards the real-world water production at scales with sorption-based AWH.