Electrochemical method was used to prepare carbon quantum dots (CQDs). Size of matter was nature when evaluate via X-ray diffraction (XRD). A distinct peak at 2θ equal to 31.6° and three other small peaks at 38.28°, 56.41° and 66.12° were observed. The measures of Fourier Transform Infrared Spectroscopy (FTIR) showed the bonds in the transmittance spectrum are manufactured with carbon nanostructures in view. The first peaks are the O–H stretching vibration bands at (3417 and 2922) cm−1, (C–O–H at 1400, and 1317) cm−1, (C–H), (C=C), (C–O–H), (C=O), and (C–O) bonds at 2850, 1668, 1101, and 1026 cm−1 sequentially. The transmission electron microscopy (TEM) results presented that the spherical CQDs are in shape and on average possess a restricted distribution of sizes of fairly 10 nm. Also, optical properties were investigated by the UV–VIS absorption spectrum, peak at 225 nm showed absorption spectrum of it. Photoluminescence emission was studied using FS-Spectrometer operating at 364 nm, 374 nm, 384 nm, 384 nm, and 404 nm wavelength to excite a broad range of quantum dots. The PL test of the top of the surface of CQDs permitted the expectation that an excessive exciting will occur at the CQDs, where the upper layer has large energy gap with small quantum dots. As a result, the optical constants are analyzed, such as the energy gap, the extinction coefficient, and photoluminescence band and its applicability in optoelectronics.
