Solar‐powered mixed‐linker metal–organic frameworks for water harvesting from arid air

Abstract

Abstract Metal–organic frameworks (MOFs) are a class of promising nanomaterials for atmospheric water harvesting (AWH), especially in arid remote areas. However, several challenges are still faced for practical applications because of the dissatisfied water adsorption/desorption properties in terms of the capability, kinetics, and stability. Herein, we report the facile synthesis of a nano‐sized octahedral nitrogen‐modified MOF‐801 that exhibits superior solar‐powered AWH performance using a custom‐made device, with a state‐of‐the‐art water harvesting ability up to 4.64LH2OkgMOFs−1 from air upon 12‐h test under a relative humidity (RH) of 30% and simulated sunlight irradiation. The nitrogen‐modified MOF‐801 with rapid sorption–desorption kinetics, uptakes 0.29gH2OgMOFs‐1 of water at 30% RH within 30 min and releases 90% of the captured water within 10 min under 1‐sun illumination. The success relies on N‐doping‐induced mixed‐linkers in the form of 2,3‐diaminobutanedioic acid and fumaric acid in the unique pore structures of the MOFs for rapid and high‐capacity water capture. The N‐doped MOF‐801 with water uptake capacity, fast adsorption kinetics, and cycle stability sheds light on the practical use of MOFs for effective solar‐powered water harvesting from droughty air.

Keywords

• adsorption kinetics
• atmospheric water harvesting
• metal–organic framework
• mixed‐linkers
• solar energy