▎ 摘　　要

NOVELTY - Method for producing blue emitting graphene quantum dots (GQDs) from coal, involves chemically oxidizing the coal in an acidic environment, followed by distillation of acid, hydrothermal cutting the oxidized coal at 175-200 degrees C for 6-8 hours to obtain a GQD solution, purifying the GQD solution through a 0.45 mm PTFE membrane, and dialyzing the filtrate of the GQD solution in 1000 Da dialysis bag. USE - The method is used for producing blue emitting GQDs from coal. ADVANTAGE - The method produces blue emitting GQDs without the use of strong acid or hazards solvent. The method synthesizes blue emitting GQDs through inexpensive facile acid-free oxidative cutting followed by neutral oxidant assisted hydrothermal method with simple dialysis tubing-based purification process. The method utilizes a precursor material (coal) which is cheap and abundantly available. The method provides a chemical oxidation synthesis route which is acid-free and simple regenerable solvent treatment process. The method is an acid/alkali and chemical solvent-free hydrothermal method. The method does not require the elimination of a large quantity of salt formed from neutralization of a strong acid or the removal of chemical solvent for purification purpose. The method ensures a moderately high (40%) product yield. The synthesized GQDs shows blue photoluminescence property with significantly high quantum yield (7.9%) efficiency than other reported coal-based work and shows a uniform distribution of particle size of 3-6 nm.