Janus PVDF-Modified Melamine Sponge Composite for High-Efficiency Solar Seawater Desalination

Solar-driven interfacial evaporation has been regarded as a promising eco-friendly strategy for desalination, but salt deposition on evaporators limits long-term stability in practical applications. Here, we present a superhydrophobic Janus solar evaporator, namely, polypyrrole-coated polyvinylidene fluoride-modified MS (PPy-PMSP), which is fabricated through a simple dipping-drying process. The PPy-PMSP achieves high light absorption and photothermal conversion, enabling an evaporation rate of 4.22 kg m–2 h–1 in simulated seawater (3.5 wt % NaCl) under 1 sun irradiation. It also exhibits excellent salt ion rejection performance in high-salinity brine conditions and a strong purification performance for organic dyes. With simple preparation, low cost, and durability, PPy-PMSP demonstrates great potential for seawater desalination and wastewater purification.