Method for preparing carbon nitride quantum dots

A method for preparing carbon nitride quantum dots comprises the following steps of (1) material preparation, (2) drying and tabletting, (3) heating, (4) separation and (5) drying. Sodium chloride crystals are used as a template, the preparing process is simple and low in cost, and the sodium chloride crystals can be easily removed through water dissolution; melamine is used as the raw material, and annular carbon nitride basic structural units exist in melamine molecules, so that the yield of preparing the quantum dots is high, and product size uniformity is good; the prepared quantum dots are high in specific area, good in water solubility and good in dispersity, have strong fluorescent radiation visible under naked eyes, and have wide application prospects in the fields of fluorescence detection, light emitting devices, biomarker and the like.