Crumpled graphene ball-based broadband solar absorbers

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Sheet-like graphene in thin films exhibits high reflectivity due to smooth microstructures.
• Graphene's stacking behavior in thin films leads to increased light reflection with thickness.
• Alternative graphene morphologies are needed to enhance light absorption for solar applications.

Purpose of the Study:

• To investigate the light absorption properties of crumpled graphene balls.
• To evaluate the performance of crumpled graphene balls as solar absorbers in interfacial evaporation systems.
• To explore the potential of crumpled graphene balls for solar heating and distillation.

Main Methods:

• Fabrication of thin films using crumpled graphene balls.
• Measurement of solar absorption spectra in the visible and near-infrared regions.
• Integration of crumpled graphene balls into an interfacial evaporation system for performance testing.

Main Results:

• Crumpled graphene balls demonstrate significantly reduced reflection compared to flat films.
• Average solar absorption reached up to 97.4% in the 350-2500 nm wavelength range.
• An evaporation efficiency of 84.6% was achieved using crumpled graphene balls as solar absorbers under one sun.

Conclusions:

• Crumpled graphene balls are strong light absorbers, suitable for solar energy harvesting.
• Their aggregation resistance and processability enhance their utility in practical solar applications.
• These findings highlight the potential of crumpled graphene balls for efficient solar heating and water distillation.