▎ 摘　　要

NOVELTY - Preparation of graphene quantum dot involves adding potassium peroxymonosulfate to a carbon material to form graphene quantum dot by a solvothermal redox reaction, a sono-Fenton reaction or a sonophoto-Fenton reaction of the carbon material. USE - Preparation of graphene quantum dot (claimed) used in bio-imaging research applications, light emitting devices and photoelectronic devices. ADVANTAGE - The method enables economical preparation of graphene quantum dot with improved purity and stability by using potassium peroxymonosulfate. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for graphene quantum dot, which has a size of 100 nm or less and a height of 10 nm or less.