High-Yield Atmospheric Water Harvesting Device with Integrated Heating/Cooling Enabled by Thermally Tailored Hydrogel Sorbent

Sorption-based atmospheric water harvesting (AWH) is regarded as a promising way to produce fresh water in water-stressed areas. However, low water production per unit device mass (WPD) and high energy consumption restrict its applications in portable fresh water replenishment. Here we report a portable high-yield AWH device based on a thermoelectric cell (TEC)-driven integrated heating/cooling thermal design, enabled by a thermally tailored hydrogel sorbent. Heat and cold energies for desorption and condensation are simultaneously generated by the TEC. Graphene oxide-doped sodium alginate hydrogel with high thermal conductivity is tailored as the sorbent, which tightly adheres to the TEC’s hot region and efficiently takes heat away, for fast desorption as well as temperature control of the TEC. Based on the thermal design of the device and materials, a total WPD of 0.18 L kg device –1 h –1 is achieved under 80% RH, almost an order of magnitude higher than that of the traditional design with the same energy input.