Solar vapor generator: A natural all-in-one 3D system derived from cattail

Solar-driven interfacial water evaporation is a promising strategy to produce fresh water by effectively converting abundant solar energy into localized heat. In this work, a natural all-in-one three-dimensional (3D) solar vapor generator (SVG) with low-cost and large-scale production based on Cattail (CT) has been proposed. The simple carbonized CT (CCT) as a photothermal material (PM) to construct the 3D SVG exhibited outstanding steam vapor generation performance due to its unique hierarchical porous architecture, rapid water transportation, high water storage capacity, enough steam escape channels and high light capture capability. When the height of CCT exposed to the environment was adjusted to be 10 cm, SVG showed an amazing water evaporation rate of 4.12 kg m−2 h−1 under 1 kW m−2 light intensity, which was higher than those of reported 3D devices, and the photothermal conversion efficiency was as high as 105.8%. The environmental energy was utilized to enhance the water evaporation performance by forming a cold evaporation surface. In addition, a device for collecting evaporated water outdoors has been designed, with an average evaporation rate of 1.04 kg m−2 h−1, about 8.32 kg m−2·day−1, demonstrating an excellent application prospect in the field of producing fresh water.