Highly Stable White-Light-Emitting Carbon Dot Synthesis Using a Non-coordinating Solvent.

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Carbon dots (CDs) are promising nanomaterials for various applications due to their unique optical properties.
• Achieving stable, dilution-independent, and excitation-independent emission in CDs remains a challenge.
• Developing novel synthesis methods for highly stable and tunable emissive CDs is crucial.

Purpose of the Study:

• To synthesize highly stable, white-light-emitting carbon dots (CDs) using a colloidal technique.
• To investigate the role of non-coordinating solvents and surface passivation in controlling CD properties.
• To report a new class of carbon dots termed "carbon onion rings".

Main Methods:

• Colloidal synthesis technique was employed for CD fabrication.
• Non-coordinating solvents were utilized to enhance CD stability.
• Surface passivation of the CD core was performed using hexadecylamine (HDA).

Main Results:

• Highly stable, white-light-emitting carbon dots (CDs) were successfully synthesized.
• Dilution-independent emissive behavior was achieved in the synthesized CDs.
• Surface functionalization with HDA minimized excitation wavelength dependence and enabled tunable blue-to-green emission.
• Synthesized CDs exhibited high inertness and stable emission spectra upon atmospheric exposure for 9 days.
• A novel type of highly crystalline carbon dots, "carbon onion rings," was discovered.

Conclusions:

• Non-coordinating solvents and HDA surface passivation are critical for fabricating highly stable and tunable CDs.
• The developed method yields CDs with desirable properties, including dilution-independent and excitation-minimized emission.
• The discovery of "carbon onion rings" opens new avenues for carbon dot research and applications.