Strain-Assisted Wafer-Scale Nanoperforation of Single-Layer Graphene by Arrayed Pt Nanoparticles

We demonstrate the large-area lithography-free ordered perforation of reduced graphene oxide (rGO) and graphene grown by chemical vapor deposition (CVD) with arrayed Pt nanoparticles (NPs) prepared by using self-patterning diblock copolymer micelles. The rGO layers were perforated by Pt NPs formed either on top or bottom surface. On the other hand, CVD graphene was perforated only when the Pt NPs were placed under the graphene layer. Various control experiments confirm that the perforation reaction of CVD graphene was catalyzed by Pt NPs, where the mechanical strain as well as the chemical reactivity of Pt lowered the activation energy barriers for the oxidation reaction of C=C bonds in graphene. Systematic atomic force microscopy and Raman analyses revealed the detailed perforation mechanism. The pore size and spacing can be controlled, and thus our present work may open a new direction in the development of ordered nanopatterns on graphene using metal NPs.