Thermoelectrically Regulating Heat Flux in Metal−Organic Framework Monoliths for High-Yield Atmospheric Water Harvesting in Arid Regions

The efficacy of atmospheric water harvesting (AWH) using metal−organic frameworks (MOFs) has been greatly hindered by insufficient heat regulation within MOFs. Herein, a sandwich-structured thermoelectric cooler (TEC)-integrated MIL-101(Cr) monolith (MOF/TEC/MOF, MTM) is developed. By leveraging the Peltier effect of TEC, the MTM allows for reversible heat transfer between its two MOF sides, simultaneously creating a cold MOF side for atmospheric water capture and a hot MOF side for water release. This not only maintains the water adsorption process at low temperatures, facilitating water adsorption at low RH, but also achieves effective recycling of water adsorption heat for water release. Benefiting from these advantages, a continuous MTM-based AWH device achieves water productivity of 3.7 L_H2O kg⁻¹ day⁻¹ at 30% RH and 25 °C. Thermoelectrically regulating heat flux in MOFs demonstrates a groundbreaking strategy for achieving high-yield AWH in arid regions.