Engineering electrothermally enhanced interfacial evaporation for high-performance solar desalination

Maximizing evaporation performance is crucial for advancing interfacial steam generation (ISG) systems, yet the potential of Joule heating for this remains underexplored. Here, we present a high-performance interfacial evaporator that leverages Joule heating-based evaporation to achieve very high water evaporation rates. The system integrates thiol-functionalized glassy carbon sponge with ultra-low electrical resistance ( ~ 0.75 Ω) to maximize joule heating. Under 1 sun illumination and a 37 W power input, the evaporator achieves an evaporation rate of ~205 kg m⁻²h⁻¹, reaching surface temperatures of 97 °C at the air-water interface. With 3.5 wt% saltwater, joule heating alone produces 11.86 kg m⁻²h⁻¹ , and combined solar (1sun)-electrothermal heating increases this to ~18 kg m⁻²h⁻¹. This work showcases the role of high electrical power in interfacial evaporation, offering a pathway for rapid and high-performance steam generation.