Assemblable Carbon Fiber/Metal–Organic Framework Monoliths for Energy-Efficient Atmospheric Water Harvesting

Abstract

Atmospheric water harvesting (AWH) with metal−organic frameworks (MOFs) represents an attractive way to alleviate water shortage stress in arid regions. However, scaling up such a concept has been partially limited by the insufficient development of the highly efficient heating and suitable processing of MOF sorbents for making them more applicable to AWH devices. To overcome these limitations, a commercial carbon fiber (CF) bundle is embedded into an Alfumarate MOF monolith assisted by a cross-linked sodium alginate (SA) network, resulting in a cylindrical CF/Al-fumarate/SA (CAS) monolith with a coaxial structure. On applying electrical power, the embedded CFs could rapidly generate enormous localized electrical heating (LEH) within a CAS matrix with exceptionally high electrothermal conversion efficiency, thereby triggering the adsorbed water in CASs to be highly efficiently released in an energy-efficient way.In particular, such CAS monoliths can be easily connected to each other in either series or parallel, forming versatile CAS assemblies with well-controlled LEH capacity. Using a serial CAS assembly as atmospheric water sorbents, a newly atmospheric water harvester has been further developed based on an LEH-driven water desorption method. The resulting prototype enables to continuously work for 7.2 water harvesting cycles per day and deliver 1.7 and 1.2 L H2O kg Al-Fum/SA −1 daily water productivity under controlled indoor and outdoor conditions, corresponding to 4.4 and 6.2 kW•h L H2O −1 energy consumption, respectively. Please note that this is the first exploration in the use of flexibly assemblable MOF monoliths and the LEH-driven water desorption method for water production with AWH, demonstrating a promising way to achieve energyefficient, scalable, low-cost, and industrially favorable AWH in arid areas.

Synergistically Enabling Fast‐Cycling and High‐Yield Atmospheric Water Harvesting with Plasma‐Treated Magnetic Flower‐Like Porous Carbons

“…This suggested that increasing the thickness of the applied P‐MFPC‐100 powder resulted in the dramatic reduction in its atmospheric water adsorption kinetics, which was mainly caused by the insufficient surface exposure of the samples to the air under such static air conditions. This phenomenon was also commonly observed in the previously reported AWH sorbents, [ 12 , 15 , 18 , 21 ] representing one of the major challenges to hinder the scaled‐up application of the sorption‐based AWH.…”

“…[ 10 ] Nevertheless, AWH sorbents including such porous carbons and MOFs exhibited desirable water uptake dynamics only if they were utilized in the form of rather thin packing layers (<5 mm). [ 10 , 12 , 15 , 16 , 17 ] Increase in the packing thickness of the implemented sorbents would cause a dramatic drop in their atmospheric water adsorption kinetics, [ 12 , 18 ] rendering significant limitations in the scale‐up water production with a compact AWH device.…”

Marine biomass-derived, hygroscopic and temperature-responsive hydrogel beads for atmospheric water harvesting and solar-powered irrigation

“…, aerogels, hydrogels, films, fabrics and sponges) is of particular interest. 46–67 Although atmospheric water is considered as a promising solution for the growing scarcity in agriculture, few sorption-based AWGs have been developed for the specific use in solar-powered irrigation. 7,33,34 Design of integrated AWG systems for energy-efficient, water-saving and self-sustaining agriculture is still beyond reach.…”

Magnetic Stuffed Bun-Structured Metal–Organic Framework Monoliths with Noncompromised Accessible Pores and Highly Efficient Recycling Capability

“…The rational choice of an industrially favorable MOF monolith and achieving its highly efficient recycling are critically important to realize the real-world AWH application of MOFs. 28 For these purposes, mSBMs consisting of a porous poly(vinyl alcohol) (PVA) wrap stuffed with UiO-66 and Fe 3 O 4 MNPs were prepared through a wetting−rolling strategy, followed by their atmospheric water adsorption and LMIH-driven water adsorption assessments. The choice of UiO-66 was based on its outstanding hydrolytic stability, thermal resistance, and excellent atmospheric water capture capacity.…”

“…AWH is among one of the most attractive applications of MOFs given their outstanding atmospheric water adsorption capability in a low-relative humidity (RH) environment and the low-energy requirement for their regenerations. − A MOF-based AWH process mainly consists of an atmospheric water capture phase and a heat-driven water desorption phase. The rational choice of an industrially favorable MOF monolith and achieving its highly efficient recycling are critically important to realize the real-world AWH application of MOFs …”