All-Day, All-Weather Desalination Using a Contactless Evaporator with Antisalt Fouling Property

Area of Science:

• Materials Science
• Renewable Energy
• Environmental Engineering

Background:

• Interfacial solar steam generation (ISSG) offers a sustainable solution for freshwater production.
• Practical ISSG is challenged by salt fouling and dependence on consistent sunlight.

Purpose of the Study:

• To develop a novel ISSG system for all-day, all-weather freshwater generation.
• To address limitations of conventional ISSG, including salt fouling and inconsistent solar illumination.

Main Methods:

• A contactless ISSG design integrating solar-reduced graphene oxide coated carbon fabric (SRGO-CF) for heat generation.
• Utilizing super hydrophilic paper walls for water transport.
• Employing low-voltage joule heating to supplement solar energy.

Main Results:

• The SRGO-CF evaporator achieved a maximum steam generation rate of 4.27 kg m⁻² h⁻¹ under solar illumination.
• Demonstrated sustained evaporation rates of 3.52 kg m⁻² h⁻¹ (with sun) and 2.32 kg m⁻² h⁻¹ (without sun) for 3.5 wt% saltwater at 2.5 V.
• Exhibited no salt fouling over extended operation periods.

Conclusions:

• The proposed contactless ISSG system effectively generates freshwater continuously, regardless of weather conditions.
• This technology overcomes key challenges in ISSG, offering a viable solution for water scarcity and enabling zero liquid discharge salt harvesting.