Comparative study of the anchorage and the catalytic properties of nanoporous TiO2 films modified with ruthenium (II) and rhenium (I) carbonyl complexes

Abstract

In this article we study the anchoring of cis-[Ru(bpyC 4 pyr)(CO) 2 (CH 3 CN) 2 ] 2+ , cis-[Ru(bpy) 2 (CO) 2 ] 2+ and cis-[Ru(bpyac)(CO) 2 Cl 2 ], onto nanoporous TiO 2 employing electropolymerization, electrostatic interaction and chemical bonding. Also, the [Re(bpyac)(CO) 3 Cl] rhenium(I) complex for chemical anchorage was analyzed. The characterization of TiO 2 /Ru(II) and TiO 2 /Re(I) nanocomposite films was performed by field emission scanning electron microscopy (FESEM), electron dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. In addition, for the more stable nanocomposites obtained, the catalytic properties (solar energy conversion and CO 2 reduction) were evaluated. The efficiency improvement in redox process derived from the (photo)electrochemical evidence indicates that modified nanoporous TiO 2 structures enhance the rate of charge transfer reactions.

Rhenium Carbonyl Molecular Catalysts for CO2 Electroreduction: Effects on Catalysis of Bipyridine Substituents Mimicking Anchorage Functions to Modify Electrodes

“…Indeed, for example, in the case of Rucarbonyl-bipyridyl complexes, the addition of an alkyl ester function on the bpy ligand has a positive influence on the catalytic activity and selectivity toward the electroreduction of CO 2 and does not prevent the formation of the active species, as we have seen above for the Re. 36,37 Note also that previous studies with rhenium triscarbonyl chloride complex with 2,2′bipyridine-4,4′-dicarboxylic acid ligand reported that this complex had no activity toward CO 2 reduction, in line with our findings. 13 Mimicking Phosphonic Anchoring Groups.…”