Pulsed-laser-deposited TiO2 nanocrystalline films supporting Au nanoparticles for visible-light-operating plasmonic photocatalysts

We have synthesized pulsed-laser-deposited (PLD) TiO2 nanocrystalline films supporting Au nanoparticles. Au films were deposited on the PLD TiO2 nanocrystalline films with the mass thickness of 4 nm. The as-deposited Au films had island structures. After furnace annealing at 300 degrees C for 180 min in air, the as-deposited island-structured Au films were balled with the mean diameter of 19 nm on the PLD TiO2 nanocrystalline films. We confirmed that the balled Au nanoparticles had the localized surface plasmonic resonance absorption band in the range of 510-600 nm. Photocatalytic activities of the Au-supporting TiO2 nanocrystalline films were evaluated by a methylene blue decomposition method. We clarified that the Au-supporting TiO2 nanocrystalline films demonstrated visible-light-driven photocatalytic activities, under the filtered (490-500 nm) Xe arc lamp irradiation.