Facile synthesis of luminescent carbon dots from mangosteen peel by pyrolysis method

Carbon dots (C-Dots) from mangosteen peel hasbeen synthesized by pyrolysis method. Synthesis of C-Dotsis done using precursor solution which is prepared fromextract of mangosteen peel as carbon source and urea aspassivation agent. C-Dots is successfully formed withabsorbance spectra at wavelength 350–550 nm. Ureaaffects to the formed C-Dots, while the absorbance and theluminescent spectra are independent toward urea. C-Dotsfrom extract of mangosteen peel has size in range~2–15 nm. The absorbance peaks of C-Dots shows significantwavelength shift at visible region as the increasingof synthesized temperature. Shift of wavelength absorbanceindicates the change of electronic transition ofC-Dots. Meanwhile, the luminescent of C-Dots can becontrolled by synthesized temperature as well. C-Dotsluminescent were increasing as higher synthesized temperature.It was shown by the shift of wavelength emissioninto shorter wavelength, 465 nm at 200 ̊ C, 450 nm at250 ̊ C, and 423 nm at 300 ̊ C. Synthesized temperaturealso affects size of C-Dots. It has size ~10–15 nm at200 ̊ C, ~7–11 nm at 250 ̊ C and ~2–4 nm at 300 ̊ C. Inaddition, temperature corresponds to the structure of carbonchains and C–N configuration of formed C-Dots frommangosteen peel extract.