Here graduate student James Radich gives a brief overview of the concept, synthesis, and implications of Holey Graphene.

2. Motivation
•Develop solution-based synthesis for porous graphene
morphology, i.e. Holey Graphene or oxidized reduced graphene
oxide (ORGO)
•Utilize gold nanoparticles (AuNP) as catalytic “nanodrills” to
generate holes in graphene sheets
•Elucidate fundamental interactions between Reduced
Graphene Oxide (RGO) and hydroxyl radicals
•Exert morphological control via reaction modulation

3. Synthesis
•UV-Peroxide system for OH radical production
•AuNP for their superior catalytic oxidation properties
•Decreases in UV-visible absorption panel D depict the oxidation of RGO
to generate holes as evident in TEM image D. (Irradiated 2 hours)

4. Confirming the Oxidation
•In Figure: (a) Au-H2O2-RGO, (b) H2O2-RGO, (c) RGO
•FTIR spectra indicate C=C attack via OH radicals
•Without AuNP ORGO is characterized by direct –OH addition to the RGO
•AuNP alleviate buildup of –OH functionalities and further catalyze the
oxidation

5. Effect of AuNP on H2O2 Photolysis
•Fluorescence intensity proportional to OH radical production
•Plot A shows 1.3x increase in OH radicals with AuNP
•Plot B depicts effect of OH radical production with incremental
increases in AuNP

6. Probing the Reaction Mechanism
•Nanosecond laser flash photolysis was used with competition kinetics to
further probe the reaction mechanism and to ascertain rate constants of
OH radical attack on RGO with and without AuNP
•kRGO = 4.4 x 109
•kAu-RGO = 1.2 x 1010

7. Proposed Reaction Mechanism

8. Reaction Modulation
•Photon-filtering reduces flux of
photons available for
photodecomposition of H2O2 to OH
radicals
•Tunable reaction and morphology

9. Conclusions and Perspectives
•A new graphene morphology, Holey Graphene, was developed
using AuNP and RGO in a solution-based synthetic scheme
•AuNP catalyze both UV photolysis of H2O2 and OH radical
attack on RGO
•Through modulation of photon flux the final ORGO
morphology can be tuned
•Significant issues are raised with regard to stability of
graphene in the presence of noble metal catalyst and oxidative
radicals (i.e. photocatalysis, fuel cells, lithium-air batteries)

10. Thank You
DOI: 10.1021/nn401794k