A Floating Integrated Solar Micro‐Evaporator for Self‐Cleaning Desalination and Organic Degradation

Abstract Safe and clean freshwater harvesting from (organic‐containing) saline or wastewater holds great potential for mitigating water scarcity and pollution, but remains challenging. Herein, a floating photothermal/catalytic‐integrated interfacial micro‐evaporator ( g ‐C 3 N 4 @PANI/PS) is reported as a proof‐of‐concept multifunctional scavenger evaporator system (MSES) to achieve both solar‐driven complete desalination and organic degradation. The spherical porous lightweight polystyrene core, incorporated with a black surface functional layer ( g ‐C 3 N 4 @PANI), enables the hybrid micro‐evaporator to naturally float and thereby collectively self‐assemble under surface tension for interfacial evaporation, which achieves preeminent self‐cleaning for complete salt/solute separation and efficient organic photodegradation under rotation. Remarkably, the floating micro‐evaporator achieves a high solar‐vapor conversion efficiency of ≈90% with high interfacial energy localization and provides abundant active photocatalytic sites on the interface, which is further enhanced by interfacial photothermal cooperation. High photo‐driven degradation efficiencies of 99% for nonvolatile organic compounds (non‐VOC) bisphenol A and 95% for VOC phenol in wastewater are achieved. An outdoor comprehensive solar water treatment test toward organic‐containing high‐salinity sewage verifies the feasibility of MSES for sustainable freshwater harvesting (1.3 kg m −2 h −1 ), downstream salt recovery, and organic degradation. This strategy may inspire an integrated solution of water scarcity, clean energy, and environmental pollution toward carbon neutrality.