Kolbe Electrochemistry in Reversible Wavefunction Engineering of Epitaxial Graphene

Abstract

Electrochemical methods to functionalize graphene have emerged as attractive protocols to covalently modify graphene in engineering a band gap and in altering its magnetic and solubility properties. Kolbe reaction, which involves the electrochemical oxidation of arylacetates (generation of α-naphthylmethyl radicals, in our present case), allows reversible grafting of radicals to graphene surface; the electro-erasing of the functional groups leads to graphene at its nearly pristine state. The surface coverage can be controlled from densely-packed (ideal as organic dielectrics) to sparsely functionalized surface (ideal for introducing reasonable band gap in graphene) with well-ordered structural patterning of the functional groups on graphene surface by fine adjustment of electrochemical conditions. Such a control of the layer structure and packing of the functional groups over the graphene surface is essential in the development of graphene applications.