Solid-state nitrogen-doped carbon nanoparticles with tunable emission prepared by a microwave-assisted method.

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Solid-state carbon nanoparticles (CNPs) offer tunable emissive properties.
• Controlling localized heating during microwave synthesis is challenging for tailoring CNP photoluminescence.

Purpose of the Study:

• To investigate the role of sample temperature in microwave-assisted synthesis of carbon nanoparticles.
• To optimize the synthesis of carbon nanoparticles with tailored photoluminescence properties.

Main Methods:

• Facile synthesis of carbon nanoparticles (CNPs) via microwave irradiation.
• Systematic variation of reaction conditions, focusing on sample temperature.
• Photoluminescence characterization, including quantum yield (QY) measurement.
• Time-dependent density functional theory (TD-DFT) calculations.

Main Results:

• Sample temperature is the critical factor controlling CNP photoluminescence, surpassing irradiation time and duty cycle.
• A green-yellowish emission with a maximum quantum yield (QY) of 14.6% was achieved at 155 °C within three minutes.
• TD-DFT calculations suggest nitrogen concentration, influenced by temperature, dictates tunable photoluminescence.

Conclusions:

• Microwave irradiation temperature is a crucial parameter for controlling the photoluminescence of carbon nanoparticles.
• This study provides a promising route for the well-controlled synthesis of luminescent CNPs.
• The findings pave the way for designing CNPs with specific optical properties for various applications.