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

Carbon dots (C-Dots) from mangosteen peel has been synthesized by pyrolysis method. Synthesis of C-Dots is done using precursor solution which is prepared from extract of mangosteen peel as carbon source and urea as passivation agent. C-Dots is successfully formed with absorbance spectra at wavelength 350–550 nm. Urea affects to the formed C-Dots, while the absorbance and the luminescent spectra are independent toward urea. C-Dots from extract of mangosteen peel has size in range ~2–15 nm. The absorbance peaks of C-Dots shows significant wavelength shift at visible region as the increasing of synthesized temperature. Shift of wavelength absorbance indicates the change of electronic transition of C-Dots. Meanwhile, the luminescent of C-Dots can be controlled by synthesized temperature as well. C-Dots luminescent were increasing as higher synthesized temperature. It was shown by the shift of wavelength emission into shorter wavelength, 465 nm at 200 °C, 450 nm at 250 °C, and 423 nm at 300 °C. Synthesized temperature also affects size of C-Dots. It has size ~10–15 nm at 200 °C, ~7–11 nm at 250 °C and ~2–4 nm at 300 °C. In addition, temperature corresponds to the structure of carbon chains and C–N configuration of formed C-Dots from mangosteen peel extract.