A facile and high-efficient approach to yellow emissive graphene quantum dots from graphene oxide

A facile and high-efficient approach for the preparation of graphene quantum dots (GQDs) is reported. With the assistance of KO 2 in the hydrothermal cutting graphene oxide (GO), a conversion rate of ∼35 wt% from GO to GQDs is achieved. The as-prepared GQDs display rarely observed yellow emissive photoluminescence with a respectable quantum yield of 8.9% in H 2 O. Moreover, the GQDs are further demonstrated to perform as a potential pH probe and bioimaging agent.