Figure 4From: Controllable size-selective method to prepare graphene quantum dots from graphene oxide Images of the morphology of GQDs-1 and GQDs-2 by AFM. (a) AFM images of GQDs-1 at the range of 5 μm. (b) Height profile and (c) height distribution of GQDs-1. (d) AFM images of GQDs-2 at the range of 5 μm. (e) Height profile and (f) height distribution of GQDs-2.Back to article page