Hierarchical Assembly of Carbon Dots with Full-Solar-Spectrum Absorption for Solar Energy Applications

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Carbon dots (CDs) offer low cost, non-toxicity, and desirable optical properties for energy applications.
• Expanding CD absorption from visible to near-infrared (NIR) is crucial for efficient solar energy harvesting.
• Current CDs struggle to utilize the entire solar spectrum.

Purpose of the Study:

• To develop hierarchical assemblies of carbon dots (HA-CDs) with full solar spectrum absorption.
• To enhance photothermal conversion efficiency for solar energy utilization.
• To demonstrate practical applications in solar-driven water evaporation and electricity generation.

Main Methods:

• Stepwise assembly of ultraviolet-absorbing CDs and visible-NIR absorbing supra-CDs (PA-CDs).
• Complexation of PA-CDs with Fe3+ ions to form 3D porous HA-CDs.
• In situ preparation of HA-CDs on fabric substrates for practical applications.

Main Results:

• HA-CDs exhibit full solar spectrum absorption and good water resistance.
• Achieved a superior photothermal conversion efficiency of 84% under simulated solar irradiation.
• Demonstrated high-performance solar-driven interfacial water evaporation, electricity generation, and cogeneration using HA-CDs-fabric.

Conclusions:

• HA-CDs provide a novel approach for high-performance photothermal materials.
• The facile Fe3+ ion cross-linking enables low-cost, scalable production of solar energy products.
• This work advances the development of carbon dot-based materials for comprehensive solar energy utilization.