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arXiv · 1103.3449

Bromination of Graphene and Graphite

A. Yaya·C. P. Ewels·I. Suarez-Martinez·Ph. Wagner·S. Lefrant·A. Okotrub·L. Bulusheva·P. R. Briddon
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Abstract

We present a density functional theory study of low density bromination of graphene and graphite, finding significantly different behaviour in these two materials. On graphene we find a new Br2 form where the molecule sits perpendicular to the graphene sheet with an extremely strong molecular dipole. The resultant Br+-Br- has an empty pz-orbital located in the graphene electronic pi-cloud. Bromination opens a small (86meV) band gap and strongly dopes the graphene. In contrast, in graphite we find Br2 is most stable parallel to the carbon layers with a slightly weaker associated charge transfer and no molecular dipole. We identify a minimum stable Br2 concentration in graphite, finding low density bromination to be endothermic. Graphene may be a useful substrate for stabilising normally unstable transient molecular states.

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A. Yaya, C. P. Ewels, I. Suarez-Martinez, Ph. Wagner, S. Lefrant, A. Okotrub, L. Bulusheva, P. R. Briddon. 2011-03-17. Bromination of Graphene and Graphite. https://doi.org/10.1103/physrevb.83.045411

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