Figure 3. Illustration of the bubbling transfer process of graphene from a Pt substrate.
(a) A Pt foil with grown graphene covered by a PMMA layer. (b) The PMMA/graphene/Pt in (a) was used as a cathode, and a Pt foil was used as an anode. (c) The PMMA/graphene was gradually separated from the Pt substrate driven by the H2 bubbles produced at the cathode after applying a constant current. (d) The completely separated PMMA/graphene layer and Pt foil after bubbling for tens of seconds. The PMMA/graphene layer is indicated by a red arrow in (c) and (d).