2023 New's Items

Water Harvesting at the Single-Crystal Level

Fuchs A
Ploetz E
Yaghi OM
2023

Metal–organic frameworks (MOFs) have emerged as a class of porous materials with facile uptake and release of water, turning them into excellent substrates for real-world atmospheric water harvesting applications. The performance of different MOF systems was experimentally characterized at the bulk level by assessing the total amount of water taken up and the release kinetics, leaving the question behind of what the upper limit of the pristine materials actually is. Moreover, recent devices rely on fluidized bed reactors that exploit the harvesting capacities of MOFs at the single-...

Green Synthesis and Scale-Up of MOFs for Water Harvesting from Air

Zheng Z
Alawadhi AH
Yaghi OM
2023

The synthetic scalability of water harvesting metal–organic frameworks (MOFs) is crucial for making these promising materials accessible and widely available for use in household devices. Herein, we present a facile, sustainable, and high-yield synthesis method to produce a series of water-harvesting MOFs, including MOF-303, CAU-23, MIL-160, MOF-313, CAU-10, and Al-fumarate. Using readily available reactants and water as the only solvent, we were able to synthesize these materials at the kilogram scale in a 200 L batch reactor with yields of 84–96% and space-time yields of 238–305 kg...

MOF Linker Extension Strategy for Enhanced Atmospheric Water Harvesting

Hanikel N
Yaghi OM
2023

A linker extension strategy for generating metal–organic frameworks (MOFs) with superior moisture-capturing properties is presented. Applying this design approach involving experiment and computation results in MOF-LA2-1 {[Al(OH)(PZVDC)], where PZVDC2– is (E)-5-(2-carboxylatovinyl)-1H-pyrazole-3-carboxylate}, which exhibits an approximately 50% water capacity increase compared to the state-of-the-art water-harvesting material MOF-303. The power of this approach is the increase in pore volume while retaining the ability of the MOF to...

High-Porosity Metal-Organic Framework Glasses

Xu W
Yaghi OM
2023

We report a synthetic strategy to link titanium-oxo (Ti-oxo) clusters into metal-organic framework (MOF) glasses with high porosity though the carboxylate linkage. A new series of MOF glasses was synthesized by evaporation of solution containing Ti-oxo clusters Ti16O16(OEt)32, linkers, and m-cresol. The formation of carboxylate linkages between the Ti-oxo clusters and the carboxylate linkers was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. The structural integrity of the Ti-oxo...

Catenated covalent organic frameworks constructed from polyhedra

Ma T
Yaghi OM
2023

Although the synthetic chemistry leading to interlocking molecular [n]catenanes of organic polyhedra (n = 2–3) and rings (n = 2–130) is established, the analogous chemistry that pertains to infinite three-dimensional systems ([∞]catenane) remains undeveloped. We report a series of [∞]catenane covalent organic frameworks (termed catena-COFs). These were synthesized by linking 4,4′-(1,10-phenanthroline-2,9-diyl)dibenzaldehyde to either of tris-(4-aminophenyl)-amine, -methane or -methanol through imine condensation. These...

High-yield, green and scalable methods for producing MOF-303 for water harvesting from desert air

Zheng Z
Yaghi OM
2022

Metal–organic frameworks (MOFs) are excellent candidates for water harvesting from desert air. MOF-303 (Al(OH)(PZDC), where PZDC is 1-H-pyrazole-3,5-dicarboxylate), a robust and water-stable MOF, is a particularly promising water-harvesting sorbent that can take up water at low relative humidity and release it under mild heating. Accordingly, development of a facile, high-yield synthesis method for its production at scale is highly desirable. Here we report detailed protocols for the green, water-based preparation of MOF-303 on both gram and kilogram scales. Specifically...

System of sequences in multivariate reticular structures

Canossa S
Yaghi OM
2023

When variance is encountered in reticular structures such as metal–organic frameworks, it occurs as multiple kinds of functionalities bound and distributed in aperiodic lattices. In these multivariate systems, unknown spatial arrangements of functionalities create properties that go beyond those of their simple sum. It is therefore essential that we learn how to recognize, study and use these arrangements, and for this purpose we propose using the concept of sequences. Accordingly, we propose a classification system, outline a method for characterizing sequences and describe the...

Functional composites by programming entropy-driven nanosheet growth

Vargo E
Xu T
2023

Nanomaterials must be systematically designed to be technologically viable1(link is external),2(link is external),...

Damage-free X-ray spectroscopy characterization of oxide thin films

Lainé A
Salmeron M
Xu T
2023

Thin polymer or oxide films(link is external) are ubiquitous components in many devices, including membranes for filtration or electrodes in electrochemical energy storage(link is external). ...

Imaging 3D chemistry at 1 nm resolution with fused multi-modal electron tomography

Schwartz J
Hovden R
Xu T
2023

Measuring the three-dimensional (3D) distribution of chemistry in nanoscale matter is a longstanding challenge for metrological science. The inelastic scattering events required for 3D chemical imaging are too rare, requiring high beam exposure that destroys the specimen before an experiment is completed. Even larger doses are required to achieve high resolution. Thus, chemical mapping in 3D has been unachievable except at lower resolution with the most radiation-hard materials. Here, high-resolution 3D chemical imaging is achieved near or below one-nanometer resolution in an Au-Fe...