Innovative 3D Janus foam design achieves high-efficiency and stable solar desalination with improved salt resistance and heat management

SDIE technology is an effective means to address freshwater scarcity, but faces challenges such as thermal management, salt scale resistance, and high energy efficiency. Herein, a 3D Janus Foam with a hydrophobic surface layer and a hydrophilic inner layer was synthesized for efficient seawater desalination. Such strategic layering provides effective thermal management, resulting in a heat loss of only ∼1.13 % throughout the photothermal conversion process. The Janus Foam’s ability to prevent salt accumulation while maintaining high evaporation efficiency over extended periods is a critical improvement over current technology. Under 1 kW m⁻², the evaporation rate of the Janus Foam is as high as 1.7898 kg m⁻² h⁻¹ with an efficiency of 96.87 %. Even under actual seawater conditions, the evaporation rate of the foam remains at 1.7426 kg m⁻² h⁻¹ with an efficiency of 91.83 %, demonstrating its high energy efficiency and adaptability to different operating environments. In conclusion, the innovative design of the 3D Janus foam offers a promising avenue for addressing global freshwater scarcity through enhanced solar interfacial evaporation processes.