Synthesis of green fluorescent, energy efficient nitrogen doped carbon quantum dots

The study of a simple and facile microwave heating technique is introduced for the synthesis of nitrogen-doped carbon quantum dots (N-CQDs) with the most abundant and cheap chemicals- Citric acid (carbon source & precursor) and Urea (nitrogen source & reducing agent). TEM and DLS results indicated that such prepared N-CQDs have an average particle size of ~0.8 nm and high Quantum Yields of ~24.69%. UV-Vis and PL Spectroscopic results indicated that these N-CQDs have bright green color fluorescence under the excitation of 405 nm wavelength and are highly dispersible inwater and providea stable optically transparent yellowish solution in ambient light. FTIR results confirmed the Nitrogen Doping over these CQDs as it consists of N-H vibrational structural bonds. XRD results display a diffraction peak at 27°, which corresponds to the (002) plane of a graphitic structure revealing an amorphous carbon phase.TEM results also demonstrated that these materials have good spherical morphology. Their high fluorescence/ photoluminescence, small size, chemical stability, high quantum yields, broad excitation range, and porous nature make them better candidates in the field of optoelectronics such as Solar cells and Light emitting diodes (LEDs), biosensing/imaging, and energy storage such as Li-Ion Batteries and supercapacitors.