3D electrostatic field coupling with copper foam hydrogel for solar-driven interfacial desalination

Solar-driven interfacial desalination is constrained by the long-standing trade-off between salt crystallization and thermal management. To address this challenge, this work proposes a 3D electrostatic field coupled copper foam hydrogel evaporator. The implantation of copper foam shortens the distance between 3D high-potential electrode and zero potential electrode, increasing the electrostatic field intensity in the gas-liquid interface area and expands the coverage of the electrostatic field. This work studies the evaporation performance and desalination capacity of the evaporator under different conditions. Results reveal that this coupled design achieves excellent evaporation increment of 22.7 % in conventional saltwater with the evaporation rate of 2.26 kg m−2 h−1, and also maintains a 12.7 % enhancement in high salinity brine at −10 kV under light intensity of 1 kW m−2. Furthermore, the maximum temperature reduction by the electrostatic field is 8.1 °C on side surface of the evaporator, improving energy utilization and mitigating radiation heat loss to the environment. The enhancement effect is better under moderate and low light intensities. This coupled design for enhancing evaporation and regulating ion migration provides a generalizable strategy for achieving energy-efficient, and salt-resistant solar desalination systems through electrostatic field assisted interfacial regulation.