AVS 61st International Symposium & Exhibition
    Surface Science Monday Sessions
       Session SS+AS+EN-MoM

Invited Paper SS+AS+EN-MoM1
Electron Trap or Atomic Hydrogen Recombination Catalyst? The Role of Metals in Photocatalysis Revisited

Monday, November 10, 2014, 8:20 am, Room 309

Session: Mechanistic Insights into Surface Reactions: Catalysis, ALD, etc.
Presenter: Francisco Zaera, University of California - Riverside
Authors: J.-B. Joo, University of California - Riverside
R.J. Dillon, University of California - Riverside
I. Lee, University of California - Riverside
C.J. Bardeen, University of California - Riverside
F. Zaera, University of California - Riverside
Correspondent: Click to Email
The production of hydrogen from water with semiconductor photocatalysts is often promoted by the addition of a small amount of a metal to their surfaces. It is commonly believed that the resulting enhancement in catalytic activity is due to a fast transfer of the excited electrons generated by photon absorption from the semiconductor to the metal, a step that prevents de-excitation back to the ground electronic state. Here we provide several pieces of evidence to argue against this mechanism. An alternative explanation is advanced where the metal acts as a catalyst for the recombination of the hydrogen atoms made via the reduction of protons on the surface of the semiconductor instead. New metal@TiO2 yolk-shell nanomaterials were conceived to test our hypothesis, and the preparation and characterization of those will be discussed in this presentation as well.