Deposition of α-SiΜο12Ο404−-[Ru(bipyridine)(terpyridine)Cl]+ multilayer film on single wall carbon nanotube modified glassy carbon electrode: Improvement of the electrochemical properties and chemical stability

A simple procedure was developed for the preparation of glassy carbon electrodes modified with single wall carbon nanotubes (SWCNTs) and multilayers of SiΜο12Ο404−-[Ru(bpy)(tpy)Cl]+(byp; bipyridine, tpy; terpyridine). Layer-by-layer deposition technique was used for the multilayer formation of SiΜο12Ο404−-[Ru(bpy)(tpy)Cl]+ onto SWCNTs films. Based on the strong electrostatic attraction of oppositely charged species a Ru-complex/poly oxometalate hybrid film strongly and irreversibly adsorbed on the glassy carbon electrode modified with single walled carbon nanotubes. The multilayer assembly exhibited good stability and excellent electrochemical reversibility for both redox systems in the pH range1-7. It was found that up to fifteen monolayers could be deposited onto a carbon nanotube film with well defined redox behavior. The modified electrode shows excellent electrocatalytic activity towards sulfite oxidation. Due to synergistic effect between SWCNTs and oppositely charged species the repeated alternate adsorption of anions and cations by this simple dipping method leads to molecular sandwiches with interesting redox activity and remarkable stability.