Superelastic Graphene Nanocomposite for High Cycle-Stability Water Capture-Release under Sunlight

The shortage of water resources is an enormous challenge for human society due to the increasing demand caused by the growing industry and population. Atmospheric water is an abundant and non-negligible freshwater resource, which can be developed as a convenient approach in some water-deficient circumstances. Herein, a graphene nanocomposite foam is designed and demonstrated for harvesting water from air by the use of solar energy. The as-fabricated foam possesses a water harvesting capability of 0.23 g g^-1 in a typical 2 h capture-2 h release cycle at 30% relative humidity, whereas 1.15 g g^-1 at 90% relative humidity. The nanocomposite foam presents a stable water harvesting performance after 10 capture-release cycles. Endowed with low density and superelasticity, the graphene nanocomposite could be compressed and portable, which takes water harvesting system one step further to practical application and commercial production.