Doping of cathodically polarized glassy carbon by natural graphite. A simple procedure for overlaying different carbons with electrochemically modifiable graphene layers.

International audienceThe redn. of graphite (at ∼-2 V vs. Ag/AgCl, in DMF contg. tetraalkylammonium salts) deposited onto smooth glassy C leads to intense graphite exfoliation that can be monitored through voltammetric scans or by fixed-potential electrolyzes (E \textless -1.8 V). These simple and extremely efficient processes result in very stable modified C surfaces exhibiting simple and astonishingly reproducible voltammetric responses (both in nature and intensity). The redn. peaks assigned to the cathodic doping of deposited graphene layers are proportional to the scan rate. The modification of these graphene-like surface structures in two types or reactions: with org. electrophiles (in the reaction with doped graphene that acts as a poly-nucleophile) or with in situ generated benzyl-type radicals were successfully achieved and compared with the results obtained on smooth C surfaces. Striking examples with addns. of hexylferrocene, benzylic derivs. of anthraquinone, anthracene and perylene, and of para-substituted benzyls (R = NO2, I, Br, F) certainly underline the interest for these new materials. [on SciFinder(R)