We report the evolution of TiO2 nanostructures when Au nanoparticles, supported on single crystal TiO2 substrates, were heated in ~2 Torr of flowing O2 in an environmental transmission electron microscope. Nanostructures with different morphologies were first observed around 500°C. Our measurements show that nanostructure growth is controlled by temperature, oxygen pressure, and the electron beam. We propose a reaction-controlled growth mechanism where mobile Ti atoms generated by the electron beam induced reduction of TiO2, are preferentially re-oxidized at the Au-TiO2 interface.
Citation: Microscopy and Microanalysis
Pub Type: Journals