Rapid and facile synthesis of graphene quantum dots with high antioxidant activity

Graphene quantum dots (GQDs) are one of most promising antioxidants owing to their fascinating properties, including favorable biocompatibility, high antioxidant activity, and low toxicity. In this work, an efficient and rapid approach for preparing GQDs was developed. The graphene oxide (GO) sheet was thoroughly fragmented into the GQDs by the hydroxyl radicals (OH•) generated from a O3/H2O2/UV oxidation reaction. GQDs possessed a large content of sp2-hybridized carbon domains and abundant functional groups in edge. The 1,1-diphenyl-2-picryl-hydrazyl (DPPH•) radical scavenging method and dye decoloration test were used to investigate the antioxidant activity of GQDs, which exhibited high antioxidant activity and great application prospects for corrosion protection, medicinal uses, and the antioxidation of organic dyes.