Sensitization of nanocrystalline TiO2 initiated by reductive quenching of molecular excited states

Citation
Dw. Thompson et al., Sensitization of nanocrystalline TiO2 initiated by reductive quenching of molecular excited states, LANGMUIR, 15(3), 1999, pp. 650-653
Citations number
19
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
LANGMUIR
ISSN journal
07437463 → ACNP
Volume
15
Issue
3
Year of publication
1999
Pages
650 - 653
Database
ISI
SICI code
0743-7463(19990202)15:3<650:SONTIB>2.0.ZU;2-N
Abstract
An alternative mechanism for dye sensitization of Ride bandgap semiconducto rs has been realized: reductive quenching of the dye excited state(s) follo wed by thermal interfacial electron transfer. The processes were identified using nanosecond-time-resolved absorption and photoluminescence spectrosco pies after selective excitation of Ru(deeb)(bpy)(2)(PF6)(2), where bpy is 2 ,2'-bipyridine and deeb is 4,4'-(COOC2H5)(2)-2,2'-bipyridine, sensitizers a nchored to a nanocrystalline (anatase) TiO2 film immersed in a 0.1 M tetrab utylammonium perchlorate acetonitrile solution with phenothiazine electron donors. With the electrolyte changed to 0.1 M lithium perchlorate, this sam e assembly undergoes the generally accepted mechanism for dye sensitization : the sensitizer excited state(s) transfer an electron to the semiconductor and is subsequently reduced by the phenothiazine donor.