▎ 摘　　要

NOVELTY - Preparing nitrogen-doped graphene quantum point (N-GQDs) using metal ion coordination catalyst, comprises (i) reacting ethanolamine and tin(IV) chloride pentahydrate, to obtain stannic oxide ligand precursor aggregate; and (ii) carrying out high temperature-high pressure carbonization, and nucleation, to obtain the final product. USE - The N-GQDs is useful in stannic oxide semiconductor material used in lithium battery, optoelectronic devices and photoelectric sensor (claimed). ADVANTAGE - The method produces product which is soluble in polar solvents, namely water, ethanol and methanol, and has good light stability, pH independence, excitation light independence (upconversion luminescence and conversion emission peak located at 415 nm, the emission peak at 220-360 nm and 550-700 nm, and positional shift between emission peaks of less than 10 nm); and has simple preparation procedures, mild reaction conditions, and good reproducibility; and overcomes the traditional preparation of product under harsh conditions, and complex multi-step reactions producing waste products (all claimed); and produces product having uniform particle diameter, thin thickness, and good crystalline property.