Electrochemical reduction of aryl diazonium salts: a versatile way for carbon nanotubes functionalisation

Single-walled carbon nanotubes (SWCNTs) possess a wealth of exceptional structural, mechanical and electronic properties. An interesting challenge is their functionalisation without altering their electronic properties by a route that ensures a stable and a strong grafting of the desired molecules. Aryl diazonium salts are promising candidates for introducing molecular tools by surface modifications. We report here the functionalisation of SWCNTs through the electrochemical reduction of aryl diazonium salts. Experiments were carried out first on a glassy carbon electrode, taking into account its low porosity and structural similarity with SWCNTs. The surface modification of both substrates is checked by electrochemical signals related to the different immobilised moieties obtained by voltammetric methods and the blocking action of the modified electrodes for Fe(CN)63-/4- redox probe in cyclic voltammetry measurements. This procedure allowed the use of a variety of diazonium salts, including those that provide moieties favourable to further elaboration after attachment to the SWCNTs. Copyright (c) 2012 John Wiley & Sons, Ltd.