One-Pot Hydrothermal Synthesis of Carbon Quantum Dots with Excellent Photoluminescent Properties and Catalytic Activity from Coke Powders.

Water-soluble, high quantum yield, green color carbon quantum dots (CQDs) are prepared by acid reflux with the use of coke powders as a carbon source. The CQDs are characterized by UV-Vis absorption spectroscopy, fluorescence spectroscopy, transmission electron microscope, fourier transform infrared spectrophotometer and x-ray diffraction. The analysis includes the evaluation of key variables with effect in the synthetic process of the quantum yield (QY) of CQDs: the reaction temperature and time, the volume of mixed acid (concentrated H2SO4 and HNO3) and the pH value on the structure and properties of as-prepared CQDs. The results revealed that the optimal hydrothermal synthesis conditions for obtaining CQDs are reaction at 100 °C for 8 h, with the volume of mixed acid is 16 mL, at pH value 9. The prepared CQDs have the activity of peroxidase-like and that quantum yield(QY)reached 34.27%.