The photochemistry of CD3I adsorbed on the TiO2(110) surface

Victor P. Holbert, Simon J. Garrett, Peter C Stair, Eric Weitz

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The photochemistry of CD3I adsorbed on the TiO2(110) surface at ∼100 K has been investigated at 257, 275, and 302 nm using modulated continuous-wave laser irradiation followed by resonantly enhanced multiphoton ionization of fragments expelled from the adsorbate layer. Photodissociation at these wavelengths produces methyl radicals by direct photolysis of those methyl iodide adsorbate molecules located at the vacuum-surface interface. The photodissociation dynamics is altered from the gas phase. Methyl radicals with velocities comparable to those observed in gas phase dissociation are detected with a narrow angular distribution consistent with a preferential alignment of the C-I bond along the surface normal. The I/I* branching ratio of these high velocity species is altered toward production of ground state iodine compared to the gas phase analogue. Collisionally slowed fragments are also observed with a much broader angular distribution. The variation in photofragment intensity with adsorbate coverage is consistent with an overlayer that grows by a statistical or stochastic process. Coverage dependent velocity distribution measurements indicate the presence of multiple adsorption phases.

Original languageEnglish
Pages (from-to)189-205
Number of pages17
JournalSurface Science
Volume346
Issue number1-3
Publication statusPublished - Feb 1 1996

Fingerprint

Photochemical reactions
Adsorbates
photochemical reactions
Photodissociation
Angular distribution
Gases
vapor phases
photodissociation
angular distribution
fragments
Continuous wave lasers
continuous wave lasers
Photolysis
stochastic processes
Laser beam effects
Velocity distribution
Iodine
Random processes
Ground state
iodides

Keywords

  • Photochemistry
  • Surface photochemistry
  • Titanium oxide

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces

Cite this

Holbert, V. P., Garrett, S. J., Stair, P. C., & Weitz, E. (1996). The photochemistry of CD3I adsorbed on the TiO2(110) surface. Surface Science, 346(1-3), 189-205.

The photochemistry of CD3I adsorbed on the TiO2(110) surface. / Holbert, Victor P.; Garrett, Simon J.; Stair, Peter C; Weitz, Eric.

In: Surface Science, Vol. 346, No. 1-3, 01.02.1996, p. 189-205.

Research output: Contribution to journalArticle

Holbert, VP, Garrett, SJ, Stair, PC & Weitz, E 1996, 'The photochemistry of CD3I adsorbed on the TiO2(110) surface', Surface Science, vol. 346, no. 1-3, pp. 189-205.
Holbert VP, Garrett SJ, Stair PC, Weitz E. The photochemistry of CD3I adsorbed on the TiO2(110) surface. Surface Science. 1996 Feb 1;346(1-3):189-205.
Holbert, Victor P. ; Garrett, Simon J. ; Stair, Peter C ; Weitz, Eric. / The photochemistry of CD3I adsorbed on the TiO2(110) surface. In: Surface Science. 1996 ; Vol. 346, No. 1-3. pp. 189-205.
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