Electrospinning Machine | Hybrid Nanofber-Based Atmospheric Water Harvesters: Sunlight-Driven Operation in Low- Humidity and Low-Illumination Environments

Challenge: Aerogels incorporated with hygroscopic salts are widely explored for atmospheric water harvesting (AWH). However, their scalability remains limited because these sorbents rely on energy-intensive and time-consuming drying methods, such as freeze-drying or supercritical drying. 

Method: Professors Guangping Han and Wanli Cheng from Northeast Forestry University collaborated with Professor Orlando J. Rojas and Researcher Yi Lu from the University of British Columbia. They confined cellulose nanofibers (CNF) and electrospun SiO2 nanofibers (SNF) within the gaps of ice crystals through freezing to form a reinforced dual-fiber network skeleton. Without using crosslinkers, ethanol was used to displace and dissolve the ice, and an ambient-pressure drying method was employed to obtain structurally intact CNF/SNF aerogels with extremely low density. 

Innovation 1: The CNF/SNF aerogel has an ultra-low density (10.86 ± 0.32 mg cm-3), a high specific surface area (104.22 m2 g-1), excellent water stability, and enhanced mechanical strength. 

Innovation 2: By incorporating carbon-based photothermal materials and lithium chloride as a hygroscopic salt, the aerogel's water uptake capacity ranged from 0.90 to 3.21 g g-1 at relative humidity (RH) levels between 15% and 75%. Under natural sunlight, the AWH aerogel produced water at a rate of 1.17 g g-1 day-1. 

https://doi.org/10.1021/acsnano.5c03322