Highly Efficient\nSolar-Driven Interface Water Evaporation\nAchieved on Polypyrrole@Single-Sided Flannel

Solar interface evaporation is considered an innovative\nand effective\ntechnology for combating global freshwater scarcity, with its effectiveness\nprimarily hinging on the efficiency of photothermal materials. Here,\nwe designed a solar evaporation device comprising a sponge layer for\nwater collection and a polypyrrole (PPy) layer chemically deposited\non a single-sided flannel (PPy@SSF) for sunlight absorption. The fiber\narray within PPy@SSF facilitates to absorb light energy, establishing\na heating interface between the light absorption layer and the water.\nThe sponge layer not only aids in water collection but also serves\nas a thermal insulation layer, preventing heat dispersion. The resulting\ndevice exhibits characteristics such as high water evaporation, robust\nstability, and resistance to salt. The daily water output reaches\n8.12 kg m<sup>–2</sup> under direct sunlight. In desalinating\nsimulated seawater, the ion concentrations in the condensed water\nwere reduced by 4 orders. Furthermore, heavy metal ions in purified\nwater from sewage were reduced by at least 3 orders of magnitude.\nAdditionally, the properties of the device showed no attenuation after\nbeing used repeatedly 10 times under 1 sun. Our research provides\na platform with high photothermal\nconversion efficiency for seawater and sewage purification.