Picosecond dynamics of surface electron transfer processes: Surface restricted transient grating studies of the n-TiO/sub 2//H/sub 2/O interface

Journal Article · Sun Jan 15 04:00:00 EST 1989 · J. Chem. Phys.; (United States)

OSTI ID:6616756

Kasinski, J J; Gomez-Jahn, L A; Faran, K J; Gracewski, S M; Miller, R J.D.

The surface restricted transient grating is demonstrated as a sensitive probe of ultrafast surface reaction dynamics. Studies of doped single crystal n-TiO/sub 2/ (001) surfaces in air demonstrate linear trapping processes, assigned to crystal defects within the surface deformation layer, that limit carrier lifetimes to 5 ns. Direct in situ grating studies at photochemically active n-TiO/sub 2//H/sub 2/O interfaces demonstrate that the dominant mechanism of interfacial electron transfer in this system involves thermalized hole carriers at the atomic surface. The dynamics are consistent with adsorbed OH/sup -/ as the initial hole acceptor. In addition, optical generation of coherent surface acoustic modes is demonstrated. A detailed theory is presented for the grating excitation of the surface acoustics. Acoustic propagation in the H/sub 2/O half-space of the TiO/sub 2//H/sub 2/O liquid interface gives evidence for a phase change of the water layer at the polar TiO/sub 2/ (001) surface to a solid phase.

• Research Organization: Department of Chemistry and the Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14627
• OSTI ID: 6616756
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 90:2; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHALCOGENIDES
CHEMICAL REACTION KINETICS
ELECTRON TRANSFER
GRATINGS
HYDROGEN COMPOUNDS
INTERFACES
KINETICS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
REACTION KINETICS
SOUND WAVES
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
WATER
WAVE PROPAGATION