A PU-supported ZrC-PPy@cellulose photothermal evaporator for efficient wastewater purification

The fabrication of sustainable solar-powered interfacial evaporators is essential for addressing global water scarcity challenges. Herein, we propose a new photothermal evaporator by applying a zirconium carbide-polypyrrole (ZrC-PPy) composite coating to a cellulose filter (CF) possessing enhanced photothermal conversion. The 3D photothermal evaporator is constructed by integrating a ZrC-PPy@CF evaporator onto triangular polyurethane (PU) foam. With a poor thermal conductivity of 0.078 W m −2  K −1 , the synthesized evaporator allowed effective heat localization under light. The evaporator produced an evaporation rate of 1.92 kg m −2  h −1 with a corresponding photothermal conversion efficiency of 89%. Additionally, the evaporator achieved over 99.9% rejection of common metal ions (Na + , K + , Ca 2+ , Mg 2+ ) from saline water, yielding high-quality freshwater. These findings highlight the ZrC-PPy@CF evaporator as a scalable and versatile platform for efficient wastewater treatment and desalination.