Precisely Ultrafast Laser-Controlled Multilevel Photothermal Well Arrays for Rapid and Salt-Tolerant Solar...

Area of Science:

• Materials Science
• Environmental Science
• Nanotechnology

Background:

• Solar-driven interfacial water evaporation is crucial for addressing the global freshwater crisis.
• Achieving high water evaporation rates alongside robust salt resistance in solar evaporators remains a significant challenge due to limited control over interfacial structures.

Purpose of the Study:

• To develop a 3D solar evaporator with precisely controlled multilevel photothermal structures for efficient and salt-tolerant desalination.
• To investigate the impact of sunflower-inspired Fibonacci spiral patterns on water evaporation and salt resistance.

Main Methods:

• Fabrication of a 3D solar evaporator (PWSE) using ultrafast laser processing on copper substrates to create multilevel photothermal well arrays.
• Designing sunflower-like Fibonacci spiral patterns for enhanced water pathway and thin film formation.
• Vertical positioning of the evaporator in a solar distiller for performance evaluation.

Main Results:

• Achieved a high water evaporation rate of 3.58 kg m⁻² h⁻¹ under one sun illumination.
• Demonstrated excellent salt resistance through gravity-driven salt particle shedding.
• Attained an optimized clean water harvesting capacity of 15.59 kg m⁻² day⁻¹ in outdoor summer conditions.

Conclusions:

• The developed PWSE, utilizing micro/nanomaterials engineering and precise structural control, significantly enhances solar desalination efficiency and salt tolerance.
• This innovative solar evaporator design offers a promising solution for sustainable water and energy.
• The study underscores the potential of biomimetic design and advanced fabrication techniques in solar water purification.