▎ 摘　　要

NOVELTY - A carbon-graphene quantum dot nanosheet composite is prepared by taking peanut shell, ultrasonic cleaning with ethanol and deionized water for 5 minutes, drying, adding hexamethylene diamine and 1.8-2.2 mol/L sodium hydroxide solution, mixing, heating at 180-220 degrees C for 4 hours, filtering, centrifuging, carrying out dialysis treatment, and drying. USE - Method for preparing carbon-graphene quantum dot nanosheet composite (claimed). ADVANTAGE - The method is simple, low-cost, environment-friendly and has high product yield. The composite is suitable for environmental, medical, food and other field chromium (III)ion fluorescence detection.