Bio-Inspired Mesoporous Solar Evaporator Enabled by Upcycled PET

Area of Science:

• Materials Science
• Environmental Science
• Renewable Energy

Background:

• Solar-driven interfacial steam generation (ISSG) is a key technology for decentralized freshwater production.
• Scalable solar evaporators face challenges in performance, environmental compatibility, and angle-insensitivity.
• Upcycling waste materials into functional devices is crucial for sustainable development.

Purpose of the Study:

• To develop a scalable, high-performance solar evaporator using recycled materials.
• To investigate a compound-eye-inspired 3D architecture for enhanced solar steam generation.
• To achieve angle-insensitive solar exposure and efficient freshwater production.

Main Methods:

• Fabrication of a graphite-containing PET nanofoam (GPF) evaporator via nonsolvent-induced phase separation from recycled PET waste.
• Construction of hemispherical multi-surface evaporators inspired by compound-eye structures.
• Performance evaluation under 1-sun illumination and outdoor natural sunlight conditions.

Main Results:

• The optimized GPF evaporator achieved a projected-area-normalized evaporation rate of 3.44 kg m^-2 h^-1 under 1-sun illumination.
• Outdoor tests yielded up to 24.4 kg m^-2 of freshwater over 14 hours.
• Enhanced performance was attributed to coupled transport and thermal effects, not just surface area enlargement.

Conclusions:

• The compound-eye-inspired 3D solar evaporator demonstrates high efficiency and stable operation.
• Upcycling waste PET into functional solar evaporators offers a sustainable route for freshwater production.
• This technology holds promise for decentralized water purification solutions.