Bio-Inspired Dual-Gradient Aerogel Enables Sustainable Freshwater Production and Energy Harvesting

Area of Science:

• Materials Science
• Renewable Energy
• Environmental Engineering

Background:

• Solar-driven interfacial evaporation and moisture-electricity generation are key for sustainable freshwater and energy.
• Integrating these into a single water and electricity co-production system (WECPS) remains a challenge.

Purpose of the Study:

• To design a dual-gradient aerogel (DGA) for efficient, salt-resistant solar evaporation and high-performance moisture-electricity generation.
• To develop a WECPS capable of simultaneous freshwater and energy production.

Main Methods:

• Engineered asymmetric ion doping using two surfactants to create an ion gradient.
• Designed hydrophilicity differences and asymmetric porosity for a water gradient.
• Fabricated a DGA-based WECPS and tested its performance in saline environments and outdoor conditions.

Main Results:

• The DGA achieved long-term salt-resistant solar evaporation and high-performance moisture-electricity generation.
• The DGA-based WECPS exhibited power densities 324-fold higher than homogeneous aerogels.
• Stable solar evaporation was maintained for seven days in saline conditions, with successful outdoor demonstrations.

Conclusions:

• The DGA-based WECPS provides an efficient and practical pathway for simultaneous water and energy co-production.
• This technology offers a self-sustaining solution for freshwater and energy challenges.
• The engineered gradients are crucial for enhanced performance in WECPS.