高性能ヤヌス型太陽蒸発器による耐塩性脱塩および有機汚染物質除去

Interfacial solar steam generation (ISSG) has emerged as a promising strategy to address the global freshwater shortage. However, its practical implementation remains limited by challenges such as inefficient thermal management, salt accumulation, and restricted evaporation rates. Here, we present a Janus-type solar evaporator with a hydrophobic photothermal top layer and a superhydrophilic bottom layer for water transport. This structure was achieved by fabricating a light-absorbing CNTs/PVDF composite membrane via an impregnation-drying method, combined with the in situ synthesis of a sodium alginate (SA) hydrogel-encapsulated melamine sponge (MS) substrate. The bilayer configuration enhances thermal localization, suppresses salt accumulation, and significantly improves evaporation performance. The evaporator achieved an evaporation rate of 3.2 ± 0.12 kg m^-2 h^-1 and a photothermal conversion efficiency of 92.2 ± 2.34% with 1 kW m^-2 solar irradiance. Even at a high salinity of 25 wt % NaCl, the device maintained a stable evaporation rate of 2.75 ± 0.15 kg m^-2 h^-1, demonstrating excellent salt resistance and long-term operational stability. This three-dimensional Janus evaporator offers a cost-effective and scalable solution for efficient solar desalination and organic pollutant removal, holding strong potential for applications in seawater treatment and industrial wastewater reuse.