Exfoliated Graphene and Ensembles with Photoactive Electron Donors for Diverse Applications

Exfoliation of graphite in a liquid phase is a top down approach to produce graphene sheets suitable for further functionalization.¹ Organic solvents were screened in parallel with sonication conditions (time and power) in the search for new and more efficient strategies toward exfoliated graphene. We will present that stable dispersions of graphene can be formed especially in o-dichlorobenzene and N-methyl pyrrolidine.² However, careful spectroscopic examination by X-ray photoelectron spectroscopy (XPS), IR and Raman revealed the presence of defects on the graphene skeleton in the form of oxygen-based functionalities.³ Moreover, we will show that the number and nature of the species introduced onto the graphene lattice can be evaluated by high-resolution XPS and we will reveal how the sonication conditions applied critically affect the quality of the so-produced graphene.³ In the following step, we will present the immobilization of photoactive electron donors, such as porphyrins and others, onto graphene via non-covalent means (supramolecularly), toward the formation of novel electron donor-acceptor systems.⁴ Finally, solid evidence for the immediate utilization of these graphene-based ensembles as photocatalysts for the removal of dyes from wastewater and water splitting for hydrogen production will be given.⁵

Acknowledgments

Partial financial support from GSRT/ESPA 2007-2013 through action “Postdoctoral support” project GRAPHCELL PE5(2126) as well as GSRT and the EC through the European Fund for Regional Development, NSRF 2007-2013 action “Development of Research Centers – ΚΡΗΠΙΣ”, project “New Multifunctional Nanostructured Materials and Devices – POLYNANO” is acknowledged.

 

References

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3. T. Skaltsas, X. Ke, C. Bittencourt, N. Tagmatarchis, J. Phys. Chem. C 2013, 117, 23272.
4. T. Skaltsas, S. Pispas, N. Tagmatarchis, Chem. Eur. J. 2013, 19, 9286.
5. T. Skaltsas, N. Karousis, N. Tagmatarchis, Submitted, 2013.