Département de chimie moléculaire

We report the functionalization of nanostructured graphene-based electrode with an original bis(2,2'-bipyridine)[4,4'-bis(4-pyrenyl-1-ylbutyloxy)-2,2'-bipyridine]osmium(II) hexafluorophosphate complex bearing pyrene groups. Graphene oxide (GO) and chem. reduced graphene oxide (c-RGO) paper electrodes were prepd. by the flow-directed filtration method. After film transfer via the sol. membrane technique, the homogeneous and stable GO electrode was electrochem. reduced in water to achieve electrochem. reduced graphene oxide (e-RGO) film on the electrode. The electrochem. properties of GO, c-RGO, and e-RGO electrodes were characterized by SEM and electrochem. Cyclic voltammetry of the Ru(NH3)62+/3+ redox probe underlines the important influence of the RGO prepn. method on electrochem. properties. We finally achieved the flexible functionalization of graphene-based electrodes using either supramol. binding of the Os(II) complex bearing pyrene groups or its electropolymn. via the irreversible oxidn. of pyrene. The properties of these functionalized graphene paper electrodes were compared to glassy carbon (GC) and multiwalled carbon nanotube (MWCNT) electrodes. Thanks to its divalent binding sites, the Os(II) complex constitutes a useful tool to probe the $π$-extended graphitic surface of RGO and MWCNT films. The Os(II) complex interacts strongly via noncovalent $π$-$π$ interactions, with $π$-extended graphene planes, thus acting as a marker to quantify the electroactive surface of both MWCNT and RGO electrodes and to illustrate their ease of functionalization. [on SciFinder(R)]