Facile hydrothermal method to prepare graphene quantum dots from graphene oxide with different photoluminescences

A simple technique to prepare graphene quantum dots (GQDs) by the hydrothermal reaction of graphene oxide (GO) sheets with hydrogen peroxide is presented. Complete removal of the hydrogen peroxide after reaction was achieved by catalytic dialysis with manganese oxide. By varying the reaction time, the particle sizes of GQDs could be controlled, leading to variations in the photoluminescence. The prepared GQDs produced stable green and blue photoluminescence. The nanostructure of the prepared GQDs was characterized and discussed in relation to its preparation procedures and behaviours of photoluminescence. The mechanism of the reaction was also discussed.