posted on 2023-11-28, 15:25authored byJiyan Li, Guoyu Xing, Min Qiao, Zihao Liu, Hanxue Sun, Rui Jiao, Lingxiao Li, Junping Zhang, An Li
Solar-driven atmospheric water harvesting
technology
has the advantage
of not being limited by geography and has great potential in solving
the freshwater crisis. Here, we first propose a purely natural and
degradable superhydrophilic composite macroporous hygroscopic material
by applying guar gum (GG) to atmospheric water harvesting. The material
consists of GG-cellulose nanofibers (CNFs) as a porous substrate material,
limiting the hygroscopic factor lithium chloride (LiCl) in its three-dimensional
(3D) network structure, and carbon nanotubes (CNTs) play a photothermal
conversion role. The composite material has a high light absorption
rate of more than 95%, and the macroporous structure (20–60
μm) allows for rapid adsorption/desorption kinetics. At 35 °C
and 90% relative humidity (RH), the moisture absorption capacity is
as high as 1.94 g/g. Under 100 mW/cm2 irradiation, the
absorbed water is almost completely desorbed within 3 h, and the water
harvesting performance is stable in 10 cycles. Moreover, liquid water
was successfully collected in an actual outdoor experiment. This work
demonstrates the great potential of biomass materials in the field
of atmospheric water collection and provides more opportunities for
various energy and sustainable applications in the future.