AVS 60th International Symposium and Exhibition
    Surface Science Thursday Sessions
       Session SS+EN-ThM

Paper SS+EN-ThM2
Anisotropic Photochemical Reactivity of Rutile (110)

Thursday, October 31, 2013, 8:20 am, Room 201 A

Session: Photocatalysis and Photochemistry at Surfaces
Presenter: A. Song, Cornell University
Authors: A. Song, Cornell University
D. Jing, Cornell University
M.A. Hines, Cornell University
Correspondent: Click to Email
The surface chemistry of nanocrystalline titanium dioxide has garnered a tremendous amount of attention over the past decade due to a number of high-profile applications, including dye-sensitized solar cells and photoactivated self-cleaning or environmentally-remediating surfaces. Since most surface science investigations study pristine surfaces in ultrahigh vacuum conditions, little is known about the photoreactivity of surfaces in aqueous solutions. In particular, do certain sites on the surface dominate reactivity or are all sites equally reactive? To gain insight into the site specificity (or chemical anisotropy) of the reactions, we have used ex situ scanning tunneling microscopy to investigate the reaction of aqueous solutions of H2O2 with rutile (110). Contrary to naïve expectation, above band gap radiation appears to suppress certain chemical reactions while also increasing reaction anisotropy. This finding suggests that some sites on the surface are more photoreactive than others. A mechanism that explains this anisotropy will be proposed.