▎ 摘　　要

NOVELTY - The extraction method of graphene quantum dots (GQDs) from carbon nanohorn as carbon source involves: (a) adding a certain amount of carbon nanohorn powder to a three-necked bottle, adding nitric acid solution with certain concentration, starting magnetic stirring, heating the mixture, carrying out heat preservation reaction, reacting, stopping the reaction, and cooling to room temperature; and (b) leaving still and settling the naturally cooled mixed solution, collecting supernate, evaporating obtained supernate, and distilling under reduced pressure to obtain a brown solid. USE - The method is useful for extracting GQDs from carbon nanohorn as carbon source (claimed). ADVANTAGE - The method extracts GQDs from carbon nanohorn with good water-solubility and fluorescent properties. DETAILED DESCRIPTION - The extraction method of graphene quantum dots (GQDs) from carbon nanohorn as a carbon source involves: (a) adding a certain amount of carbon nanohorn powder to a three-necked bottle, adding nitric acid solution with certain concentration, starting magnetic stirring, heating the mixture at 80-120 degrees C, carrying out heat preservation reaction, reacting for 24-48 hours, stopping the reaction, and cooling to room temperature; (b) leaving still and settling the naturally cooled mixed solution, collecting supernate, evaporating obtained supernate, and distilling under reduced pressure to obtain a brown solid; (c) dispersing the brown solid in a certain amount of ionized water to form a turbid liquid, centrifuging the suspension at a speed of 10000-15000 rpm for 30-60 minutes, and collecting the supernate; and (d) carrying out dialysis on the supernate using a dialysis bag with molecular weight cut-off of 0.5-3 kDa, collecting a solution in the dialysis bag, and carrying out vacuum drying at 60-80 degrees C for 24-48 hours to obtain product.