Efficient cathodic carboxylation of graphene.
Résumé
CO2 is known to be poorly reactive under cathodic conditions. When glassy carbon-graphene electrodes are put in contact with a satd. soln. of CO2 in DMF contg. tetrabutylammonium salts (TBAX) and polarized at potentials \textless -1.7 V vs. Ag/AgCl (i.e. before own redn. of CO2), their redn. steps vanish and a large sudden inhibition takes place during further recurrent scans. This suggests that the principal electrode reaction is the cathodic charge of graphene resulting in poly-nucleophilic species followed by their reaction with electrophilic CO2 in soln. A quite dense poly-carboxylation of the material is chem. confirmed. The grafting of a large panel of reactive electrophiles (eventually carrying a redox group) on these graphene-based carboxylate-covered surfaces was achieved and allowed on the easy building of a wide variety of modified electrodes. The enhanced hydrophilicity of those materials renders possible their use in aq. media. [on SciFinder(R)]