a1 LeRoy Eyring Center for Solid State Science, Arizona State University, Tempe, AZ 85287, USA
a2 Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 68101, USA
a3 National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
a4 School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287, USA
We report the evolution of titanium dioxide nanostructures when Au nanoparticles, supported on single crystal TiO2 substrates, were heated under ∼260 Pa of flowing O2 in an environmental transmission electron microscope. Nanostructures with different morphologies were first observed around 500°C. Our measurements show that temperature, oxygen pressure, and the electron beam control the nanostructure growth. We propose a reaction-controlled growth mechanism where mobile Ti atoms generated by the electron- beam-induced reduction of TiO2 are preferentially reoxidized at the Au-TiO2 interface.
(Received June 09 2010)
(Accepted November 15 2010)
(Online publication February 01 2011)
p1 See Wee Chee is currently at Rensselaer Polytechnic Institute, Troy, New York
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