Engineering of Defective MOF-801 Nanostructures within Macroporous Spheres for Highly Efficient and Stable Water Harvesting.

Abstract

Water harvesting using the metal-organic framework (MOF)-801 is restricted by limited working capacity, powder structuring, and finite stability. To overcome these issues, wecrystallized MOF-801 on the surface of macroporous poly(N-isopropylacrylamide-glycidyl methacrylate) spheres, called P(NIPAM-GMA), through an in situ confined growth strategy, forming spherical MOF-801@P(NIPAM-GMA) composite with temperature-responsive function. By lowering the nucleation energy barrier, the average size of the MOF-801 crystals decreased by 20 times. Thus, abundant defects as adsorption sites for water couldbe installed in the crystals lattices. As a consequence, the composite provides an unprecedented high water harvesting efficiency. The composite wasproduced in the kilogram-scale and can capture 1.60kg H2 O/kg composite/day from 20% RH between 25°C and 85°C. This work provides an effective methodology for improving the adsorption capacity through controlled defects formation as adsorption sites and to improve the kinetics through the design of a composite with macroporous transport channel network. This article is protected by copyright. All rights reserved.