Hydrophilic Photothermal Polydopamine/Polyurethane Foam for Efficient Solar-Driven Water Evaporation

Abstract

Solar-driven seawater desalination is considered an promising technology coping with water scarcity due to the sustainability of solar energy and its substitutability for fossil fuels. Nevertheless, the complex fabrication, high cost and low efficiency of solar-driven evaporator limit its large-scale application. Herein, the PDA/PU composite foam with porous three-dimensional structure is developed to achieve low cost and high-efficient solar-driven water evaporation. Thereinto, hydrophilic PDA contributes to the real solar energy absorption, and provides an extremely high photothermal conversion efficiency. Meanwhile, the porous PU foam provides excellent capillary effect for sufficient water supply. The as-fabricated PDA/PU foam can reach 77.8°C and 48.1°C under the laser and simulated solar irradiation (1 kW/m²), respectively. Further, the specific water evaporation rate is 1.93 kg/m² h⁻¹ under simulated solar irradiation. Therefore, the PDA/PU foam exhibits effective solar-driven water evaporation rate which provides inspiration for the future development of high-performance seawater desalination devices.