Green synthesis of fluorescent carbon nanoparticles from lychee (Litchi chinensis) plant

摘要

Fluorescent carbon nanoparticles (CNPs) were prepared from waste lychee peel by hydrothermal process using green chemistry. These CNPs were characterized by UV-vis absorption, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. Their morphology was analyzed by field emission scanning electron microscopy. Spherical carbon nanoparticles with a particle size ranging from 40-70 nm were observed. FTIR data indicated that these CNPs were functionalized with hydroxyl and carboxylic or carbonyl group. The maximum fluorescence intensity for these CNPs was observed on the excitation wavelength at 365 nm with emission maxima centered at 450 nm. These particles exhibited excitation wavelength dependent fluorescence emission spectra. CNPs were found to be highly fluorescent and exhibited high water solubility. The band gap was estimated to be 3.8 eV. Therefore, as prepared CNPs would be useful in bioimaging, biolabeling and in the other applications of nanobiotechnology.