An All-Passive\nand Macropatterned Architecture Design\nfor Water Harvesting

Solar evaporation designs show great promise in water\nharvesting\nwithout electricity inputs. Unfortunately, they have been heavily\nlimited by a low water yield. To overcome this challenge, we introduced\na new architecture featuring both system-level and materials-level\ndesigns. At the system level, we implemented a macropatterned architecture\nwith a decoupled design for water evaporation and condensation to\nenhance water yield efficiency. This design also ensures that condensed\nwater droplets do not block the solar evaporation process. At the\nmaterials level, solar selective heating and radiative cooling were\napplied to improve passive water yield performance. As a proof of\nconcept, our design showed an indoor water collection rate of 2.06\nkg m<sup>–2</sup> h<sup>–1</sup> under one sun and an\naverage outdoor water collection rate of 1.85 kg m<sup>–2</sup> h<sup>–1</sup> over five consecutive days. The decoupled,\nall-passive, and macropatterned architecture offers substantial potential\nfor commercial water collection applications toward mitigating global\nwater scarcity.