Photoinduced interfacial electron transfer within a mesoporous transparent conducting oxide film.
Interfacial electron transfer to and from conductive Sn-doped In2O3 (ITO) nanoparticles (NPs) in mesoporous thin films has been investigated by transient absorption measurements using surface-bound [Ru(II)(bpy)2(dcb)](2+) (bpy is 2,2'-bipyridyl and dcb is 4,4'-(COOH)2-2,2'-bipyridyl). Metal-to-ligand charge transfer excitation in 0.1 M LiClO4 MeCN results in efficient electron injection into the ITO NPs on the picosecond time scale followed by back electron transfer on the nanosecond time scale. Rates of back electron transfer are dependent on thermal annealing conditions with the rate constant increasing from 1.8 × 10(8) s(-1) for oxidizing annealing conditions to 8.0 × 10(8) s(-1) for reducing conditions, presumably due to an enhanced electron concentration in the latter.
Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States.
Byron H
BH
Farnum
Zachary A
ZA
Morseth
Alexander M
AM
Lapides
Adam J
AJ
Rieth
Paul G
PG
Hoertz
M Kyle
MK
Brennaman
John M
JM
Papanikolas
Thomas J
TJ
Meyer