Hygroscopic salt-embedded composite materials for sorption-based atmospheric water harvesting

Shan, He (author), Poredoš, Primož (author), Chen, Zhihui (author), Yang, Xinge (author), Ye, Zhanyu (author), Hu, Zhifeng (author), Wang, Ruzhu (author), Tan, Swee Ching (author)

Sorption-based atmospheric water harvesting has the potential to address water scarcity by extracting fresh water from the air. The performance of this technology largely depends on the sorbent used. Hygroscopic salt-embedded composite materials (HSCMs) are promising sorbents for sorption-based atmospheric water harvesting because they combine the high sorption capacities of hygroscopic salts across all relative humidity levels with the salt-retaining structure and kinetics-enhancing properties of a porous or networked matrix. However, the interactions between the matrix and salts in HSCMs are not yet fully understood, which hinders the rational design of their sorption performance. This Review introduces a framework for understanding key sorption characteristics — capacity, enthalpy, kinetics and stability — of HSCMs, through an in-depth thermodynamic analysis of the interactions among hygroscopic salts, water and salt solutions. Using this framework, we analyse reported HSCMs and guide the design of future composites by considering factors such as salt content, pore structure and the carrying capacity of the matrix. We also examine the energy flow within the sorption and desorption cycles to explore potential designs for the matrix that could enhance both aspects. Looking forward, we emphasize the importance of designing sorbent materials and multifunctional device systems in tandem, integrating material design needs, local water demand and energy efficiency to fully leverage the untapped capabilities of atmospheric humidity.

• Language: English
• Keywords: atmospheric water harvesting, solar energy, hygroscopic salts, composite sorption materials, kinetics of sorption/desorption, dynamics of sorption/desorption, daytime radiative sky cooling materials, radiative heat exchange, spectrally selective materials, heat and mass transfer, renewable energy sources
• Work type: Article
• Typology: 1.02 - Review Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 699-721
• Numbering: Vol. 9
• PID: 20.500.12556/RUL-165024
• UDC: 536:502.21:523.9
• ISSN on article: 2058-8437
• DOI: 10.1038/s41578-024-00721-x
• COBISS.SI-ID: 215882499
• Publication date in RUL: 21.11.2024

Record is a part of a journal

• Title: Nature reviews : Materials.
• Shortened title: Nat. rev., Mater.
• Publisher: Nature Publishing Group
• ISSN: 2058-8437
• COBISS.SI-ID: 528594457

Secondary language

• Language: Slovenian
• Keywords: atmosfersko pridobivanje vode, sončna energija, higroskopske soli, kompozitna sorpcijsko sredstva, kinetika sorpcije/desorpcije, dinamika sorpcije/desorpcije, materiali za sevalno hlajenje z nebom, sevalna izmenjava, spektralno selektivni materiali, prenos toplote in snovi, obnovljivi viri energije