Large scale production of graphene quantum dots through the reaction of graphene oxide with sodium hypochlorite

Graphene quantum dots (GQDs) assume unique chemical/physical properties owing to their single atomic layered structure and quantum confinement. A facile and effective approach to the large scale production of GQDs is highly demanded to facilitate their wide applications. In this work, we demonstrated that graphene oxide (GO) reacted with sodium hypochlorite (NaClO) under UV irradiation and the reaction could be applied to generate GQDs. The reaction proceeded very quickly and GQDs could be obtained in a few minutes. The as-generated GQDs possess high crystallinity. More strikingly, the yield of GQDs prepared through the reaction of GO with NaClO is the highest in terms of all the methods developed so far, up to 78% in weight. The results of fluorescence behavior studies revealed that the as-obtained GQDs exhibit stronger fluorescence emission, compared with that prepared though the photo-Fenton reaction of GO we proposed in our previous work. Moreover, it was clarified that the oxygen-containing groups on the plane of GQDs played a key role on the fluorescence behavior.