Selective functionalisation of active carbons surfaces by electrochemical grafting

摘要

The surface chemistry of activated carbons is actually playing an important role in all the processes where they are used, I.e.Adsorption, catalysis and supercapacitor electrodes. Therefore, the control of the chemical nature of the surface, by itsfunctionalisation with particular chemical groups, could be a way to improve their performance for several applications andto open new application routes. In the present work, an electrochemical procedure for derivatizing carbon surfaces, which hasbeen extensively used for grafting on the surface of highly ordered pyrolytic graphite (HOPG) platelets, is presented for highsurface activated area carbons, in which not many studies has been reported. The method consists in an anodic oxidation overcarbon electrodes of molecules, such as carboxylates or alcohols, giving a radical that will be coupled to the carbon surfacevia a covalent bond. By selecting the appropriate functional substituent on the carboxylate or alcohol molecules, we are ableto link several kinds of chemical groups to the carbon surface. The nature and the amount of the grafted groups ischaracterised by cyclic voltammetry, elemental analysis, XPS and thermal programmed desorption (TPD), proving theselectivity and efficiency of the method proposed over activated carbons.