Sintesis Dan Karakteristik Optik Carbon Quantum Dot Yang Berasal Dari Asam Sitrat Dengan Variasi Massa Urea

Abstract

Carbon quantum dot (CQD) is a semiconductor carbon material with a size smaller than 10 nm. CQD has many benefits in the fields of sensors, LEDs, drug delivery, biomedicine industry, fluorescence, solar cells, etc. This study synthesizes CQD with an up and down method using microwave radiation. Sample derived from citric acid was given 1 gr, 1.7 gr, 2.4 gr, and 3.2 gr of urea. Furthermore, the sample was tested using ultraviolet-visible (UV-Vis) spectroscopy and fluorescence spectroscopy. From the spectra, we analyzed the optical properties consisting of theamount of absorption, gap energy, the intensity of its fluorescence.UV-Vis spectra of CQD extends between 300 nm and 822 nm. Fluorescence excitation wavelengths range from 360 -800 nm. The determined energy gaps of the CQD by using touch plot method are 2.3 eV and 2.4 eV.

Synthesis and Characterization of Optical Properties of Carbon Quantum Dots (CQD) Based on Mustard Green (Brassica juncea L) Leaf with Urea Addition

“…Then, the model was optimized with the DFT method and calculated the optical properties with the TDDFT method. Calculations were performed using Orca 5.0 software 21 .…”