rGO samples were synthesized by Hydrothermal reduction of graphene oxide (GO), which is a promising approach for GO reduction since it is environmentally friendly, simple and cost effective.
Before the hydrothermal treatment, a monolayer or a few-layer GO could be achieved after dispersing in water, in which the thickness of a single layer was measured to be 0.8–0.9 nm, as observed by AFM (Fig(a)).
The GO layered structure was observed at the beginning of treatment. The number of layers reduces with the increase in reduction time, the layered nature becomes disordered, crumpled and smaller.
rGO samples treated at (a) GO, rGO (b) 30 min, (c) 1 h, (d) 2 h, (e) 4 h, (f) 6 h, (g)8 h, (h) 10 h.
Scanned with a OLYMPUS OMCL-AC240TM
AFM probe on a Bruker MutiMode 8 AFM system.
Image courtesy of Dr. Masamichi Yoshimura, Toyota Technological Institute