Laser-Assisted Scalable Pore Fabrication in Graphene Membranes for Blue-Energy Generation

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Blue energy, derived from salinity gradients, is a promising renewable source but hindered by poor membrane performance.
• Atomically thin 2D nanoporous materials offer high performance but face fabrication and ion concentration polarization challenges.
• Mesoporous and microporous 2D membranes show potential for improved energy generation with simpler fabrication.

Purpose of the Study:

• To develop a scalable fabrication method for creating larger pores in graphene membranes for blue energy generation.
• To investigate the potential of femtosecond laser-assisted fabrication for enhancing osmotic power generation.

Main Methods:

• Utilized femtosecond (fs) laser-assisted fabrication to create micro- to millimeter-sized pores on graphene membranes.
• Fabricated pores ranging from micrometer to millimeter in size on graphene for osmotic power generation.

Main Results:

• Achieved remarkable osmotic power in the microwatt (μW) range using millimeter-sized pores, a significant increase over nanoporous membranes.
• Demonstrated a six-orders-of-magnitude increase in osmotic power compared to nanoporous membranes due to diffusion-osmosis driven ionic flux.
• Successfully fabricated scalable pores on graphene membranes for blue energy applications.

Conclusions:

• Femtosecond laser-assisted fabrication offers a viable route for scalable pore creation in 2D membranes for efficient blue energy harvesting.
• Larger pores (mm-size) in graphene membranes significantly enhance osmotic power generation, addressing limitations of nanoporous designs.
• This work paves the way for large-scale osmotic power generation using advanced 2D membrane technologies.