One-Pot, Optimized Microwave-Assisted Synthesis of Difunctionalized and B-N Co-Doped Carbon Dots: Structural...

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Carbon dots (CDs) are emerging nanomaterials with tunable optical properties.
• Co-doping CDs with elements like nitrogen (N) and boron (B) can enhance their photoluminescence and functionality.
• Efficient synthesis methods are crucial for scalable production and application of B-N co-doped CDs.

Purpose of the Study:

• To develop a novel microwave-assisted synthesis for nitrogen and boron co-doped carbon dots (B-N co-doped CDs).
• To optimize synthesis parameters (temperature, time, precursor concentration) for maximum fluorescence emission.
• To characterize the synthesized B-N co-doped CDs and explore their potential applications.

Main Methods:

• Microwave-assisted synthesis with systematic parameter modulation (temperature, time, precursor concentration).
• Characterization using Field Emission Scanning Electron Microscopy (FESEM), High-Resolution Transmission Electron Microscopy (HRTEM), UV-vis absorption, fluorescence spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS).
• Optimization based on maximum fluorescence emission.

Main Results:

• Optimal synthesis conditions identified: 120 °C, 3 min, 1 mg/mL precursor concentration.
• Synthesized B-N co-doped CDs exhibit spherical morphology (10.9 ± 3.38 nm) and graphitic structure (interplanar distance 0.23 nm).
• Achieved a high quantum yield of 56.7% with an emission peak at 375 nm (excitation 295 nm), confirmed N and B co-doping and functional groups (boronic acid, amine).

Conclusions:

• Microwave-assisted synthesis is an effective method for producing B-N co-doped CDs with desirable optical properties.
• The synthesized B-N co-doped CDs possess characteristics suitable for applications as fluorescent probes and in cell imaging.
• Further theoretical investigations supported the proposed structure and doping of the synthesized carbon dots.