▎ 摘　　要

Herein, we report an in situ synthesis of graphene quantum dots (GQDs), which have been synthesized from only starch and water and stabilize AuNPs in water. The construction of six gold nanocomposites, i.e. AuNPs 1-6, with sizes ranging from 13.4 nm to 32.6 nm, was accomplished by only mixing the GQDs and chloroauric acid in different amounts without any additional reductants and surfactants. HRTEM has confirmed that the AuNPs have been stabilized by the GQDs, and a core/shell AuNPs@GQD structure has formed. In addition, the as-synthesized AuNPs show excellent catalytic performance in the reduction of 4-nitrophenol, a pertinacious pollutant occurring in industrial wastewater.