Controllable and Reversible Dispersiblity of Graphene Materials by a Generic Organometallic Functionalization

A general and reversible functionalization method has been developed for reduced graphene oxide (rGO) based on a simple reaction sequence. In this sequence, the chemical functionalization of reduced graphene oxide (rGO) was first carried out by a nucleophilic addition of n-butyllithium (n-BuLi) to rGO sheets, followed by a subsequent coupling step of intermediates (n-Bu-rGO)n-Li(n+) with alkyl halide, leading to functionalized rGO with controllable and reversible dispersiblity in either nonpolar or polar solvents depending on the functional groups. Next, the functional groups could be reversibly removed by solvothermal treatment to generate reduced graphene sheets. Then the reduced materials could be again functionalized using the same reaction sequence above with either the same or different functional groups to almost the same extent of the first functionalization cycle.