Polyelectrolytic Cellulose Nanocrystals Enabled Efficient Atmospheric Water Harvesting

Atmospheric water harvesting (AWH) technology is a promising strategy to provide sustainable water for arid regions. Hygroscopic biomass nano/gel materials are considered ideal AWH materials because of their renewability and tunable structures. However, the insufficient hydrophilicity and slow adsorption-desorption kinetics of biomass sorbents are big challenges for realizing efficient AWH. Here, an efficient polyelectrolytic strategy of cellulose nanocrystals with poly(acrylic acid) (SCNCPA) using Ce4+ initiated for high-performance AWH devices is demonstrated. Benefiting from the high grafting yield similar to 206%, the rigid SCNCPA network coordinated with highly carboxylated surface similar to 11.5 mmol g(-1) have sufficient physisorption and chemisorption sites to capture water rapidly. Using an elastic fabric EF as the skeleton, assisted by small amounts of hygroscopic salt similar to 20 wt %, the SCNCPA based-EF AWH device showed excellent AWH performance, the moisture sorption and desorption capacity similar to 1.27 g g(-1) at 30% relative humidity, and produced similar to 8.4 L kg(-1) of fresh water per day. This strategy provides new insights for the sustainable and valuable design of the AWH system.