Novel Sponge-Based\nCarbonaceous Hydrogel for a Highly\nEfficient Interfacial Photothermal-Driven Atmospheric Water Generator

A high-performance atmospheric water generator based\non continuous\nadsorption–desorption of liquid hygroscopic agents was constructed\nby applying interfacial photothermal evaporation technology to the\nfield of atmospheric water harvesting. A three-dimensional carbon-containing\nsponge hydrogel photothermal conversion material with a porous channel\nstructure was designed, which was prepared from melamine foam (MF)\nand carbon black (CB) cross-linked by sodium alginate (SA). The results\nshowed that the evaporation rate of CB/SA@MF in pure water was 1.90\nkg·m<sup>–2</sup>·h<sup>–1</sup>, and the\nphotothermal conversion efficiency could reach 85.0%. The multistage\npore structures and water transport channels in the A4 configuration\ndevice provided an excellent structural basis for material salt resistance\nand liquid hygroscopic agent regeneration. Using sponge-based CB/SA@MF\nhydrogel photothermal composites as the evaporation interface and\nliquid hygroscopic salts as the air–water trapping agent, an\ninterfacial photothermal-driven atmospheric water generator successfully\nabsorbed water at night and produced water during the day. Its water\nproduction could reach 2.84 kg·m<sup>–2</sup>·d<sup>–1</sup>. The cost of the atmospheric water generator was\nonly $12, and the water quality obtained after 5 cycle tests met WHO/GB\n5749-2022. This research was designed to collect fresh water from\nthe air, bringing convenience to inland arid regions as well as remote\nand scattered areas with limited power resources.