Rapid solar-driven atmospheric water-harvesting with MAF-4-derived nitrogen-doped nanoporous carbon

• Published in: Chemical science (Cambridge) 2024-06, Vol.15 (25), p.9557-9565
• Main Authors: Feng, Jin-Hua, Lu, Feng, Chen, Zhen, Jia, Miao-Miao, Chen, Yi-Le, Lin, Wei-Hai, Wu, Qing-Yun, Li, Yi, Xue, Ming, Chen, Xiao-Ming
• Format: Article
• Language: English
• Subjects: Carbon; Chemistry; Graphitization; Humidity; Relative humidity; Sorption; Sunlight; Thermal conductivity
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d4sc01802h

Sorption-based atmospheric water-harvesting (AWH) could help to solve global freshwater scarcity. The search for adsorbents with high water-uptake capacity at low relative humidity, rapid adsorption-desorption kinetics and high thermal conductivity is a critical challenge in AWH. Herein, we report a MAF-4 (aka ZIF-8)-derived nanoporous carbon (NPC MAF-4 -800) with multiple N-doped sites, considerable micropore characteristics and inherent photothermal properties, for efficient water production in a relatively arid climate. NPC MAF-4 -800 exhibited optimal water-sorption performance of 306 mg g −1 at 40% relative humidity (RH). An excellent sunlight-absorption rate was realized (97%) attributed to its high degree of graphitization. A proof-of-concept device was designed and investigated for the practical harvesting of water from the atmosphere using natural sunlight. NPC MAF-4 -800 achieved an unprecedentedly high water production rate of 380 mg g −1 h −1 at 40% RH, and could produce 1.77 L kg −1 freshwater during daylight hours in an outdoor low-humidity climate of ∼25 °C and 40% RH. These findings may shed light on the potential of MOF-derived porous carbons in the AWH field, and inspire the future development of solar-driven water-generation systems. A MOF-derived nanoporous carbon (NPC MAF-4 -800) with multiple N-doped sites, considerable porous characteristics and inherent photothermal properties demonstrated a superior water-production rate under a relatively arid climate.