Home >
News > Water harvesting from air with metal-organic frameworks powered by natural sunlight
Water harvesting from air with metal-organic frameworks powered by natural sunlight
Summary:
The authors from Massachusetts Institute of Technology, University of California–Berkeley, etc. (United States) developed MOF-801 with low-humidity water adsorption, low-energy desorption, and recyclability, achieving 2.8 L·kg⁻¹·day⁻¹ water harvesting in air at 20% RH via natural sunlight.
Background:
1. To address global water scarcity and limitations of existing water-harvesting methods (dew collection needs 100% RH, fog capture is energy-intensive; porous materials have low uptake or high desorption energy), previous researchers studied zeolites, silica gels, and MOFs, yet failed to balance efficiency and energy consumption.
2. The authors proposed using MOF-801 (with well-defined water adsorption, cluster-based performance, and stability) and solar-driven desorption, realizing low-RH, low-energy air water harvesting.
Research Content:
1.Synthesis: The authors synthesized MOF-801 powder as reported, then activated it by heating at 150°C under vacuum for 24 hours, and infiltrated it into porous copper foam to form an adsorbent layer.
2.Characterizations:
1) No explicit BET/pore size data; MOF-801 has three symmetric cavities, packing porosity ~0.85.
2) SEM/TEM tests show MOF-801 crystal diameter ~0.6 μm.
3) Water adsorption: 0.25 kg·kg⁻¹ at 25°C/20% RH; solar absorptance of the absorber ~0.91.
3.Application: Tested in environmental chambers (0.24 L·kg⁻¹ per cycle) and outdoor prototypes (MIT roof, ~0.3 L·kg⁻¹ harvestable), achieving 2.8 L·kg⁻¹·day⁻¹ at 20% RH.
4.Mechanism: MOF-801’s cavities trap water into clusters; solar heat (≤1 kW·m⁻²) drives desorption; condenser collects water, forming a passive adsorption-desorption cycle.
Outlook:
This research develops a solar-powered MOF-801 water-harvesting system, solving low-RH water-scarcity issues and providing a sustainable solution for arid regions.
Water harvesting from air with metal-organic frameworks powered by natural sunlight
Authors: Hyunho Kim, Sungwoo Yang, Sameer R. Rao, Shankar Narayanan, Eugene A. Kapustin, Hiroyasu Furukawa, Ari S. Umans, Omar M. Yaghi, Evelyn N. Wang
DOI: 10.1126/science.aam8743
Link: http://science.sciencemag.org/content/early/2017/04/12/science.aam8743
The above review is for academic progress sharing. For any errors or copyright issues, please contact us for correction or removal.
