▎ 摘　　要

NOVELTY - Nitrogen-doped graphene quantum dot derived from nanomaterial-lignin, comprises 1-3 wt.% nanomaterial lignin powder, 3-5 wt.% yttrium oxide powder, 5-7 wt.% alumina powder, and 87-89 wt.% silicon nitride powder. USE - The nitrogen-doped graphene quantum dot derived from nanomaterial-lignin useful in field of biological medicine (claimed). ADVANTAGE - The method is simple and short; and no toxic substances are generated in the conversion process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the nanomaterial-lignin-derived nitrogen-doped graphene quantum dot, comprising (i) uniformly mixing the above raw materials and drying to obtain the composite powder; and (ii) placing the uniformly mixed composite powder into the mold for pre-pressing, and sintering at 1600-1800 degrees C with a pressure of 20-40 MPa under the protection of nitrogen atmosphere, maintaining heat preservation and pressure for 30-40 minutes, heating at 750-850 degrees C, maintaining the temperature for 30-60 minutes.