Engineering electrothermally enhanced interfacial evaporation for high-performance solar desalination

Area of Science:

• Materials Science
• Chemical Engineering
• Renewable Energy

Background:

• Maximizing evaporation performance is critical for interfacial steam generation (ISG) systems.
• The role of Joule heating in ISG has been underexplored.
• Developing efficient evaporators is key for practical ISG applications.

Purpose of the Study:

• To present a high-performance interfacial evaporator utilizing Joule heating for enhanced steam generation.
• To investigate the impact of ultra-low electrical resistance materials on evaporation rates.
• To explore combined solar and electrothermal heating for increased water evaporation.

Main Methods:

• Fabrication of a thiol-functionalized glassy carbon sponge evaporator with ultra-low electrical resistance (~0.75 Ω).
• Testing the evaporator under 1 sun illumination with a 37 W power input.
• Measuring evaporation rates for pure water and 3.5 wt% saltwater under different heating conditions.

Main Results:

• Achieved an evaporation rate of ~205 kg m⁻²h⁻¹ under combined solar and electrothermal heating.
• Reached surface temperatures of 97°C at the air-water interface.
• Joule heating alone produced 11.86 kg m⁻²h⁻¹ for saltwater, increased to ~18 kg m⁻²h⁻¹ with solar assistance.

Conclusions:

• High electrical power input significantly enhances interfacial evaporation rates.
• The developed evaporator demonstrates a promising pathway for rapid and high-performance steam generation.
• Joule heating offers a viable strategy to boost the efficiency of interfacial steam generation systems.