Cost-Effective 3D-Printed Bionic Hydrogel Evaporator for Stable Solar Desalination

Area of Science:

• Materials Science
• Environmental Engineering
• Renewable Energy

Background:

• Solar desalination is crucial for sustainable freshwater production.
• Existing hydrogel evaporators face challenges in cost-effectiveness, scalability, and salt resistance.
• Need for advanced materials and designs for efficient and stable solar desalination.

Purpose of the Study:

• To design and develop a cost-effective and scalable 3D-printed bionic hydrogel evaporator (3DP-BHE) for stable solar desalination.
• To mimic natural transpiration and hierarchical porous structures for enhanced performance.
• To evaluate the long-term performance and cost-effectiveness of the 3DP-BHE.

Main Methods:

• Fabrication of 3DP-BHE using commercial activated carbon and biomass starch skeleton.
• Incorporation of a bionic tree leaf layer for light absorption and vapor diffusion.
• Design of a bionic tree trunk layer with a 3D printed bimodal porous structure for water transport and ion management.
• Testing under one sun (1 kW m⁻²) solar irradiation with 10 wt.% brine.

Main Results:

• The 3DP-BHE achieved 94.01% light absorption and a stable evaporation rate of 2.13 kg m⁻² h⁻¹ at 90.5% energy efficiency.
• During 7-day desalination of 10 wt.% brine, a steady evaporation rate of 1.98 kg m⁻² h⁻¹ was maintained.
• Demonstrated record-high cost-effectiveness of 195.3 g h⁻¹ $⁻¹ with a material cost of $10.14 m⁻².

Conclusions:

• The 3DP-BHE offers a promising, affordable, and scalable solution for solar desalination.
• The bionic design enhances light absorption, water transfer, and salt ion management for stable long-term performance.
• This technology has significant potential for freshwater production in various scales, including households and off-grid communities.