Nanofabrication and characterization of green-emitting N-doped carbon dots derived from pulp-free lemon juice extract

In this work, highly fluorescent green-emitting N-doped carbon dots (N-CDs) were derived from pulp-free lemon juice extract, as a green precursor, through a one-pot carbonization at 180 oC for 3 to 5 h. The newly fabricated N-CDs were thoroughly characterized using different imaging and analytical techniques, including Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Fluorescence spectroscopy, X-ray diffraction analysis (XRD), and Ultraviolet-visible (UV-Vis) spectroscopy. The preliminary evaluation showed that N-CDs synthesized at 180 ºC for 3 and 5 hours emit bright green light under UV or blue light irradiation with a quantum yield of 16.33% and 21.80%, respectively. The fluorescence spectroscopic profiles revealed that as-developed N-CDs exhibit excitation-independent photoluminescence (PL) emission at 365 nm. FTIR profile reveals the functional group entities with evident peaks in 3190 cm¿1, 1660 cm¿1, 1580 cm¿1, 1405 cm¿1, 1365 cm¿1, 1190 cm¿1, and 1060 cm¿1 regions, among others that correspond to the presence of N-H, C-H, C=O and C=N, C=C, C-H, COOH, C-O-C, and C-O. SEM unveils uniform and well-crystalline morphology of N-CDs.. © The Author(s), 2023.