Described is the preparation of transparent nanostructured TiO2 (anatase) and Sb-doped SnO2 films supported on F-doped conducting glass. Also described is the modification of these films by chemisorption of RV, bis(4,4-bis(phosphonomethyl)-2,2-bipyridine)(5-((1-ethyl-4,4-bipyridinediium-1-yl)butyl)-2,2-bipyridine)ruthenium- (II) tetrakis(hexafluorophosphate), to form the covalent heterosupramolecular assemblies TiO2-RV and SnO2- RV, respectively. Visible light excitation of the ruthenium complex component, R, results in electron injection into the TiO2 or SnO2:Sb nanocrystal component (60%) and electron transfer to the viologen component (40%), V. In the case of TiO2-RV, however, long-lived formation of the radical cation of the V component, V¥+, is observed. In the case of SnO2-RV, long-lived formation of V¥+ is not observed. These findings, based on a detailed study of the time-resolved optical spectroscopy of TiO2-RV and SnO2:Sb-RV, are accounted for by proposing that long-lived V¥+ is formed by TiO2 nanocrystal mediated electron transfer to the V component.
Time-Resolved Optical Spectroscopy of Heterosupramolecular Assemblies Based on Nanostructured TiO2 Films Modified by Chemisorption of Covalently Linked Rutheniumand Viologen Complex Components
SCANDOLA, Franco;
2001
Abstract
Described is the preparation of transparent nanostructured TiO2 (anatase) and Sb-doped SnO2 films supported on F-doped conducting glass. Also described is the modification of these films by chemisorption of RV, bis(4,4-bis(phosphonomethyl)-2,2-bipyridine)(5-((1-ethyl-4,4-bipyridinediium-1-yl)butyl)-2,2-bipyridine)ruthenium- (II) tetrakis(hexafluorophosphate), to form the covalent heterosupramolecular assemblies TiO2-RV and SnO2- RV, respectively. Visible light excitation of the ruthenium complex component, R, results in electron injection into the TiO2 or SnO2:Sb nanocrystal component (60%) and electron transfer to the viologen component (40%), V. In the case of TiO2-RV, however, long-lived formation of the radical cation of the V component, V¥+, is observed. In the case of SnO2-RV, long-lived formation of V¥+ is not observed. These findings, based on a detailed study of the time-resolved optical spectroscopy of TiO2-RV and SnO2:Sb-RV, are accounted for by proposing that long-lived V¥+ is formed by TiO2 nanocrystal mediated electron transfer to the V component.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.