Vibrational Excitations and Low Energy Electronic Structure of Epoxide-decorated Graphene

E C Mattson; J E Johns; K Pande; R A Bosch; S Cui; M Gajdardziska-Josifovska; M Weinert; J H Chen; M C Hersam; C J Hirschmugl

doi:10.1021/jz4025386

Vibrational Excitations and Low Energy Electronic Structure of Epoxide-decorated Graphene

J Phys Chem Lett. 2014 Jan 2;5(1):212-219. doi: 10.1021/jz4025386.

Authors

E C Mattson¹, J E Johns², K Pande¹, R A Bosch³, S Cui⁴, M Gajdardziska-Josifovska¹, M Weinert¹, J H Chen⁴, M C Hersam⁵, C J Hirschmugl¹

Affiliations

¹ University of Wisconsin-Milwaukee, Physics Dept., Milwaukee, WI 53211.
² University of Minnesota, Chemistry Dept, Minneapolis, MN 55455.
³ Synchrotron Radiation Center, University of Wisconsin-Madison, Stoughton, WI 53589.
⁴ University of Wisconsin-Milwaukee, Mechanical Engineering Dept., Milwaukee, WI 53211.
⁵ Northwestern University, Chemistry Dept., Evanston, IL 60208 ; Northwestern University, Materials Science and Engineering Dept., Evanston, IL 60208.

Abstract

We report infrared studies of adsorbed atomic oxygen (epoxide functional groups) on graphene. Two different systems are used as a platform to explore these interactions, namely, epitaxial graphene/SiC(0001) functionalized with atomic oxygen (graphene epoxide, GE) and chemically reduced graphene oxide (RGO). In the case of the model GE system, IR reflectivity measurements show that epoxide groups distort the graphene π bands around the K-point, imparting a finite effective mass and contributing to a band gap. In the case of RGO, epoxide groups are found to be present following the reduction treatment by a combination of polarized IR reflectance and transmittance measurements. Similar to the GE system, a band gap in the RGO sample is observed as well.

Keywords: adsorbates; band structure; epitaxial graphene; oxygen; reduced graphene oxide; vibrations.

Grants and funding

T32 AR007611/AR/NIAMS NIH HHS/United States